I’m using SQL Server Reporting Services 2008 R2 CTP, more precisely version 10.50.1352.12, but the methods explained here will work on any SSRS 2008.  Furthermore I’m using the AdventureWorks2008R2 database, available at CodePlex.

The resulting report, including image files, can be downloaded from my Skydrive.

The Scenario

The marketing department has requested a product catalogue.  This catalogue should contain all products produced by our two daughter companies: The Canyon Peak and Great Falls Soft.  The catalogue should be grouped on company, with the next company’s products starting on a new page.

Further requirements are:

1. Each page needs an image in its header, with even pages displaying a different image than odd pages.
2. Each company has a logo.  The logo should be displayed in the company’s header.
3. Each product has a logo.  The logo should be displayed as part of the product details.

A design document containing the expected layout, including all image material, has been provided.

The Data

The following query provides us with all the data needed to produce the report:

SELECT 'The Canyon Peak' as Company, 'TheCanyonPeak_logo.png' CompanyLogo,
    'The Canyon Peak company specializes in all kinds of bikes, such as touring and road bikes.' CompanyDescription,
    P.Name as Product, PS.Name as Subcategory, PC.Name as Category,
    PP.LargePhoto, P.ListPrice, P.Weight, P.Size,
    P.SizeUnitMeasureCode, P.WeightUnitMeasureCode
FROM Production.Product AS P
    INNER JOIN Production.ProductSubcategory AS PS
        ON PS.ProductSubcategoryID = P.ProductSubcategoryID
    INNER JOIN Production.ProductCategory AS PC
        ON PC.ProductCategoryID = PS.ProductCategoryID
    LEFT OUTER JOIN Production.ProductProductPhoto PPP
        ON PPP.ProductID = P.ProductID
    LEFT OUTER JOIN Production.ProductPhoto PP
        ON PPP.ProductPhotoID = PP.ProductPhotoID
WHERE PC.Name = 'Bikes' --The Canyon Peak sells bikes
    and PP.ProductPhotoID > 1 --I don't want NO IMAGE AVAILABLE
UNION ALL
SELECT 'Great Falls Soft' as Company, 'GreatFallsSoft_logo.png' CompanyLogo,
    'Great Falls Soft uses only the softest tissues available for those sporting clothes.  And on top of that, they''re waterproof.' CompanyDescription,
    P.Name as Product, PS.Name as Subcategory, PC.Name as Category,
    PP.LargePhoto, P.ListPrice, P.Weight, P.Size,
    P.SizeUnitMeasureCode, P.WeightUnitMeasureCode
FROM Production.Product AS P
    INNER JOIN Production.ProductSubcategory AS PS
        ON PS.ProductSubcategoryID = P.ProductSubcategoryID
    INNER JOIN Production.ProductCategory AS PC
        ON PC.ProductCategoryID = PS.ProductCategoryID
    LEFT OUTER JOIN Production.ProductProductPhoto PPP
        ON PPP.ProductID = P.ProductID
    LEFT OUTER JOIN Production.ProductPhoto PP
        ON PPP.ProductPhotoID = PP.ProductPhotoID
WHERE PC.Name = 'Clothing' --Great Falls Soft sells clothes, waterstopping soft clothes
    and PP.ProductPhotoID > 1 --I don't want NO IMAGE AVAILABLE
ORDER BY Category asc, Subcategory asc, Product asc;

I’m not going into the details of this query.  Let’s just say that I’m manipulating data from the database in combination with some hardcoded data to get usable data for our example.  I’ve added some comments to make it clear what the query is doing.  If you have a look at its output, you’ll see that it produces a list of products with some additional fields.

Different Ways Of Adding Images

To get started, open up a SSRS solution, add a new report, add a data source connecting to your AdventureWorks 2008 R2 DB, and add a dataset using the above query.

Embedding Images In Your Report

The first way of adding images to a report that we’ll take a look at is by embedding them inside the report.  Looking at the scenario requirements described earlier, this is requirement 1.

Let’s add a header to the report.  In the BIDS menu, select Report > Add Page Header.

If you don’t see the Report menu item, you probably have not selected your report.  Click your report in the Design view to select it.

From the Toolbox, drag the Image report item onto the header portion of the report.  Doing that will show a pop-up window, the Image Properties.  By default, the Select the image source combobox is set to Embedded.  Good, that’s what we need at this point.  What we now need to do is import an image into the report, using the Import button.

Clicking the Import button shows a common file Open dialog.  Our marketing department has given me two images for use in the header: Cloudy_banner.png and AnotherCloudy_banner.png.  Let’s select the first one.

If you don’t see any images, have a look at that filter dropdown as highlighted in the screenshot above.  By default this is set to JPEG files.

Here’s the result in the Image Properties:

On the Size page, select Clip instead of Fit proportional.  This is a setting that you’ll need to look at case per case.  For our header images, Clip is the most suitable option.

Close the Image Properties window and enlarge the image placeholder so that it occupies the whole header area:

As you can see, we now have an image in the header.  But we haven’t fully implemented the requirement yet.  The even pages should display a different image than the uneven ones.

To be able to do that, we’ll first add the second banner image to the report.  In the Report Data pane, locate the Images node and open it up.  You’ll notice that the image that we inserted earlier can be found here.

Right-click the Images node and select Add Image.

That opens up the familiar file Open dialog which was used to add the first image.  So I’m now selecting the file called AnotherCloudy_banner.png, after changing the default filter to PNG.  After clicking OK, the image gets added under the Images node.

With the second image added, all that remains to be done is tell the header that it should pick different images depending on the page number.

Right-click the image in the header and select Image Properties.  On the General page, when you click the dropdown of the setting called Use this image, you’ll notice that there are two values now.  These are the same values as displayed in the Report Data pane.  And these are the values to be used in the expression that we’ll create to rotate the images depending on page number.

Click the fx button next to the dropdown and enter the following expression:

=IIF(Globals!PageNumber Mod 2 = 0, "Cloudy_banner", "AnotherCloudy_banner")

This is a fairly simple expression, using the Mod operator and the IIF() function.  When page number can be divided by two, which means it’s an even page number, Cloudy_banner is displayed.  Otherwise the other banner is displayed.

That’s it, the report header is finished.  When you have a look at the report in Preview, it should now show the second banner on the first page – this is an uneven page.

To conclude this chapter I’d like to mention that this method is usually not the preferred one.  A disadvantage here is that the images are stored inside the report RDL and thus cannot be modified without altering the report itself.

Here’s the evidence:

 <EmbeddedImages>
    <EmbeddedImage Name="Cloudy_banner">
      <MIMEType>image/png</MIMEType>
      <ImageData>iVBORw0KGgoAAAANSUhEUgAABVsAAABaCAIAAA...

To have a look at the RDL yourself, just right-click the report in the Solution Explorer and select View Code.

On to requirement number two!

Displaying Images Through A URL

At the moment, the report body is still empty, so drag a Table onto it.  Put the Table in the upper-left corner, remove one of the columns so that two remain, remove the Header row and make it a bit wider.

Now set the DataSetName property of the Tablix to the name of your dataset, in my case that’s dsProducts.

The report should display the data grouped on company, so right-click on the line that says Details in the Row Groups window part at the bottom of the Design View.  Select Add Group > Parent Group.

Group by Company and add a group header:

Remove the extra first column that just got generated:

We’ve now got an empty tablix with two columns, a Details row and a Company header row.  In our dataset, one of the fields is called CompanyDescription.  Hover the mouse pointer above the textbox in the top-right, click the small icon that appears and choose the field from the dropdown that appears when you click the icon.

To add the company’s logo, drag an Image from the Toolbox pane into the textbox on the left of the company description.  Doing this opens up the by now familiar Image Properties dialog.

Give it a good name, such as CompanyLogo, and select External as image source.

Click the fx button next to the Use this image box and enter an expression such as this one:

="file:C:\vavr\test\" + Fields!CompanyLogo.Value

When using External as image source, the image expression should result in a valid URL, any valid URL.  In my example the files are located in a local folder called c:\vavr\test.  Keep in mind that, when you deploy the report to a server, the images should by located in that same folder, this time located on the server.

By default the image gets displayed using the Fit Proportional setting.  You can verify this in the Size page of the Image Properties.  We want the image to get fully displayed while maintaining the aspect ratio, so leave the setting as it is.  Close the image properties dialog.

Vertically enlarge the first row in our tablix to an acceptable size.  In my case the marketing department specified to use a height of 1.5 inches for the company logo.  With the image selected, locate the Size > Height property and set it to “1,5in”.  Note that the decimal separator used here depends on your local settings.

Now have a look at the report in Preview:

Note that I’ve removed the borders of all textboxes by setting their BorderStyle property to None.

With the logo images implemented we have fulfilled requirement two.  On to number three.

Retrieving Images From The Database

In this last requirement we’ll have a look at displaying images that are retrieved from the database, also known as data-bound images.

The retrieving part is actually already implemented.  In our dataset there’s a field called LargePhoto, that one contains a picture of the product.

Let’s add some product details and a picture in that remaining blank row.  To get full control over layout I want to make the detail part of the tablix a freestyle part.  First merge the two cells together by selecting both of them, then right-click and choose Merge Cells.

Now select a Rectangle in the Toolbox pane and drop it into the merged area.  To add fields such as Subcategory and Product you can just select them from the Report Data pane and drop them inside the rectangle.  I’m also adding some additional labels and fields, as shown in the next screenshot.

As you can see I’ve modified the fonts a bit.  The rendered version:

This is the expression used for displaying the weight:

=IIF(
    IsNothing(Fields!Weight.Value),
    "unknown",
    Fields!Weight.Value & " " & Fields!WeightUnitMeasureCode.Value
)

And here’s the expression for the size field:

=Fields!Size.Value & " " & Fields!SizeUnitMeasureCode.Value

For the layout the price field I’ve just entered C in the Format property of the textbox.

With the textual product details completed, all that remains to be done is adding the product image.

From the Toolbox pane, drag an Image into the remaining whitespace in the rectangle, next to the product details.  (You did keep some space available, right?)

Again we get the familiar Image Properties popup.  Give it a good name, like ProductImage, and select the image source that we haven’t used yet, Database.  In the Use this field dropdown, select LargePhoto, and select image/gif as MIME type.

Note: the images are stored as GIF.  You can verify this by running a select on the Production.ProductPhoto table.  Looking at the LargePhotoFileName field we see that the extension is .gif.

There one textbox on the General page that’s still blank.  That one is called Tooltip.  Click the fx button next to it and enter following formula:

=Fields!Product.Value

Click sufficient OK buttons until the properties dialog is gone, then resize the image placeholder so that it occupies the remaining whitespace.

Here’s what the result looks like in preview:

When hovering the mouse pointer above the product image, you’ll get a nice tooltip.

Conclusion

In this article I have illustrated the three possible methods of adding an image to your Reporting Services report.

Have fun!

Valentino.

References

BOL: Adding Images to a Report

I’ll be starting from the report that I created in Your First OLAP Report.  That allows me to focus on the visualization part, without first needing to build a table report.  (Okay, I admit, it’s not 100% the same report – I’ve modified the colors a bit because I felt the green was too dark.) But obviously this method will work with any report that’s showing data in a table.

Furthermore I’m running SQL Server 2008 R2 Nov CTP, 64-bit, and I’m using the BIDS to develop the report.

The final result can be downloaded from Skydrive here.

Implementing The Data Bar

The report that we’re using is showing some sales figures grouped in three levels: Country, State/Province and City.  We’re going to add an extra column on the right of the table to contain the data bar.  Let’s first explore the Toolbox pane to discover the new visualization report items.

The new items have been highlighted in yellow.  As you can see, besides Data Bar there’s also Sparkline, Map and Indicator.  But those are not on topic now.

To add a Data Bar, simply drag it from the Toolbox into a textbox on the report.  Doing that will show the following popup window:

From left to right, there’s Bar, Stacked Bar and 100% Stacked Bar.  And those are also available in vertical direction, Column.  I’m going to use the regular Bar as highlighted in the screenshot.

The Data Bar has now been added to the report, but it doesn’t do anything yet.  We first need to tell it what data to visualize.  Clicking it once will select it, clicking it once more will show us the following Chart Data popup:

Click the plus icon to get a drop-down of fields in the dataset.  Select the numeric field that you want to visualize, in my case that’s the Reseller_Sales_Amount.

By default, the aggregation used on the data is Sum.  But there are other options as well, have a look at the dropdown next to the [Sum(Reseller_Sales…  In the example here I’m going to keep the Sum.

The report Preview looks like this:

In this report we can easily see what states have got a higher sales amount: those with the longer bars.

Let’s add bars for the Country level as well.  There are two ways to achieve that: you can either drag a new Data Bar onto the report or you can just copy/paste the textbox containing our first Data Bar.

To make the report easier to read I will change the color of the Data Bar to the color of the group’s background.  Setting up the color of the Data Bar is done as follows: select the Data Bar so that you get the Chart Data popup.  In the Properties pane you should see that the Chart Series is selected.  Then right-click on the bar and select Series Properties.

In the Series Properties window, select the Fill page and select your favorite color.  If you want you can also use a gradient fill or pattern.  You can even use a Switch statement and color them differently depending on their value, similar to the method that I used in my SSRS and MDX: Detecting Missing Fields article.  Well, in short, any expression that you can think of and results in a color will work fine!

With the second data bar and custom coloring set up, here’s the rendered report:

Hang on, is that correct? As you can see, the data bar for California is longer than the one for Canada while the sales amount for Canada is definitely the higher one.  An even nicer example is United Kingdom with only one state England.  Both amounts are equal yet their data bars are certainly not.

Well, this is because the data bar by default uses the same scope as the group where it’s put.  Canada and United Kingdom are in the Country group and all Country data bars compare nicely to each other.  California and England are in the State/Province group and also compare nicely to each other!

Depending on the report’s requirements this may or may not be the desired effect.  But I wouldn’t be mentioning this if there weren’t any other options, would I?

Setting The Maximum Value Of The Horizontal Axis

A correct column label for our current column would be “% of group”.  Let’s add a second column which will show the percentage of the row compared to the total of the dataset, “% of overall total”.  After adding the extra column, copy/paste the data bars from the first column over into the new textboxes in the second column.

To get what we want, we need to tell the data bar that the maximum for the horizontal axis is the total of the dataset and not the total of the grouping level of the table.  So, right-click one of the data bars in the new column and select Horizontal Axis Properties.

As you can see, the default for the Maximum value is set to “Auto”.  Note that the name of my tablix is “Tablix1”, as shown in the Align axes in dropdown.

Let’s replace the Auto as Maximum with the following expression:

=Sum(Fields!Reseller_Sales_Amount.Value, "Tablix1")

This expression says that we need the sum of the Reseller_Sales_Amount, scoped over the whole tablix.

Having changed the Maximum value on both data bars gives us the following preview:

As you can see, this time around the data bars for England and United Kingdom have gotten the same size.  Bars from different grouping levels can now be compared with each other.

Showing Labels On The Data Bars

In this report it would be interesting to add a label that displays the percentage to the status bars, so let’s do that.

For the percentage calculation of the first column of data bars we need to get the total of the current group and divide that by the total of the group one level higher.  For the State/Province level that gives us the following expression:

=Sum(Fields!Reseller_Sales_Amount.Value)
    / Sum(Fields!Reseller_Sales_Amount.Value, "grpCountry")

The grpCountry refers to the name of the grouping one level higher, as shown in following screenshot:

And for the Country level we need this expression:

=Sum(Fields!Reseller_Sales_Amount.Value)
    / Sum(Fields!Reseller_Sales_Amount.Value, "Tablix1")

The only difference with the previous expression is the scope.

“Ok, so where do I type those expressions?” I hear you think.  Right-click the Data Bar (after first selecting the textbox that contains it) and choose Show Data Labels.

That adds a label to the chart but we still need to configure it to show the percentage.  By default it uses the value as label.  This can be verified in the Chart Series properties:

The UseValueAsLabel is set to True, confirming what I just stated.  Furthermore, activating the Show Data Labels option also set the Visible property to True.  So another way of adding the label is by just setting this property to True.

Let’s now configure that label.  Right-click it and select Series Label Properties.

The General page of the Series Label Properties window allows you to define the Label data.  That’s where you need to enter the expression that I mentioned earlier.

After you’ve entered the expression, the BIDS will ask you if you want to set the UseValueAsLabel to False, so click Yes.

With the label selected as shown in the next screenshot you can use the formatting toolbar buttons to give it a decent font and all.

For our second column of data bars the expressions need to take into account that we need the percentage as compared to all the data, unrelated to the level.  This actually makes it easier because we can use the same expression on both the State/Province and Country level.  Furthermore, it’s exactly the same expression as the one used on Country level in the first data bar column (i. e. the second expression above) because Country is the highest level.

Let’s have a look at the result in preview:

Woah, looks like we forgot something doesn’t it?  We forgot to format the label as being a percentage!  There are two ways to get that done: through the Number page on the Series Label Properties window:

Or by using the properties with the label selected (the Properties pane should show Chart Series Labels in the dropdown on top):

I’ve opted for a percentage without any decimals.

Let’s have another look at that report:

That sure looks better doesn’t it?  The status bars on the right compare over the grouping levels while those on the left compare with each other within the same group.  And they all have a clear label indicating what they represent.

Have fun putting those data bars on your reports!

Valentino.

References

BOL 2008R2: What’s New (Reporting Services)

BOL 2008R2: Sparklines and Data Bars

An Introduction to Data Bars in SQL Server Reporting Services 2008 R2

Now that SQL Server 2008 R2 has been RTM’ed, it’s time to demonstrate new functionality in SSRS that allows the retrieval of data from another dataset, a dataset not linked to your data region.  It’s not completely the same as actually joining two datasets, but it’s better than nothing – and it works!

In this article I’ll show you how exactly this works by using the new Lookup, LookupSet and MultiLookup SSRS functions.

I’m using the AdventureWorks 2008R2 relational database and the AdventureWorksDW 2008R2 data warehouse, available from CodePlex.  The main data is coming from the data warehouse while all the lookups are done on the relational database.

Setting Up A Basic Table Report

In my report I’ve created a dataset called dsInternetSales.  This dataset is retrieving data from the AdventureWorksDW2008R2 data warehouse using the following query:

select PROD.EnglishProductName, PROD.ProductAlternateKey, PROD.ListPrice,
    PSC.EnglishProductSubcategoryName, PC.EnglishProductCategoryName,
    S.OrderQuantity, S.SalesAmount
from FactInternetSales S
inner join DimProduct PROD on S.ProductKey = PROD.ProductKey
inner join DimProductSubcategory PSC
    on PROD.ProductSubcategoryKey = PSC.ProductSubcategoryKey
inner join DimProductCategory PC on PSC.ProductCategoryKey = PC.ProductCategoryKey

Using that dataset, I’ve set up a Table as shown in following screenshot.

The Details group has been set up to group on ProductAlternateKey.  On top of the Details group, I’ve grouped on EnglishProductSubcategoryName and the top-level group is grouping on EnglishProductCategoryName.  The Order Quantity column is displaying the sum of the OrderQuantity values for each ProductAlternateKey.

The result is a report that shows all (internet) sales per product, without any filtering.  Very useful report if you want to know how many items your company has sold since it’s existence.  Okay, management would probably like to see some filtering on here, but that’s not the purpose of this article.

Here’s what it looks like in Preview:

Adding Data From Another Database

Imagine now that you need to add an extra line under each product, containing the product description.  But this description is not available in the data warehouse.  In fact it could even be stored on another server.

In the example here we will retrieve the description from the AdventureWorks2008R2 relational database.

Setting Up The Second Dataset

I’ve created an additional dataset called dsProductInfo, using the following query:

select P.ProductNumber, PD.Description
from Production.Product P
inner join Production.ProductModel PM on P.ProductModelID = PM.ProductModelID
inner join Production.ProductModelProductDescriptionCulture PMPDC
    on PMPDC.ProductModelID = PM.ProductModelID
    and PMPDC.CultureID = 'en'
inner join Production.ProductDescription PD
    on PMPDC.ProductDescriptionID = PD.ProductDescriptionID

Not only does it retrieve the product’s description, we’re also fetching the ProductNumber.  Here’s what part of the result looks like:

The reason that we’re retrieving ProductNumber as well is because it matches with the ProductAlternateKey which we’ve retrieved earlier in our first dataset.  And this is very important because that’s the key on which we’re going to link the datasets.

Using The Lookup Function

I’ve added an additional row inside the Details group and inserted a Placeholder to retrieve the product’s description, using the new Lookup function.

So, what does the Placeholder’s expression look like?  Here it is:

=Lookup(
    Fields!ProductAlternateKey.Value,
    Fields!ProductNumber.Value,
    Fields!Description.Value,
    "dsProductInfo"
)

As you can see, the Lookup function requires four parameters.

The first parameter is the key value in your current dataset, the dataset used by the table data region.  In our case that’s the ProductAlternateKey field in the dsInternetSales dataset.

The second parameter is the name of the key field in the second dataset, the one on which the lookup will happen.  In our case that’s the ProductNumber in the dsProductInfo dataset.

The third parameter is the field from the second dataset that you’re wanting to retrieve using the lookup, in our case the Description field from dsProductInfo.

And finally, the last parameter is the name of the dataset on which you want to do the lookup.

Please note that parameter number four is a string parameter, so the value needs to be enclosed by double quotes.  If you forget about that, you’ll get a couple of nice error messages like these:

[rsInvalidLookupScope]  The Value expression for the textrun ‘Textbox29.Paragraphs[0].TextRuns[0]’ has a scope parameter that is not valid for a lookup function. The scope parameter must be set to a string constant that is the name of a dataset.

So, don’t forget the quotes.

With the Lookup call set up as explained, here’s the updated report Preview:

How cool is that huh?  Each product has gotten a description, retrieved from another database, and still in the same table data region.  Before R2 of SQL Server 2008, this wasn’t possible to achieve (well, not easily anyway) and now it’s actually fairly simple!

Is that all?  Ha, I was kinda hoping that you were going to ask that.  No, it’s not all, there are two more new lookup functions: LookupSet and MultiLookup.

More Lookups: The LookupSet Function

In case you’re wondering, in the Expression Builder the new lookup functions are located under the Miscellaneous node:

Let’s say that you want to add another detail row, this time it needs to show all colors in which the product is manufactured.  Again this additional info is coming from the AdventureWorks relational database.

I’ve created a dataset called dsProductColors using the following query:

select distinct LEFT(P.ProductNumber, 6) as ProductCodeWithoutColorAndSize,
    P.Color
from Production.Product P
where P.Color is not null

When looking at the product codes, I noticed that for the products which are available in several colors and sizes, the last four characters represent the color and size.  Which means the first six characters define the product itself, without color or size.  That’s why the query is using the Left function to create a product code of only the first six characters of the ProductNumber.  Using the distinct keyword, we remove any duplicate records.

(Please note that I’m not 100% sure if this logic applies to all products but for this demo it’s fine.)

Here’s what the query retrieves:

As you can see, for some products there’s more than one record.  And that’s exactly what the LookupSet function was made for: it retrieves a set of data based on the key given to it.  This is different from the Lookup, where for each key value it would fetch only one value.

Again I’ve added an additional row inside the Details group and used a placeholder with the following expression:

=Join(
    LookupSet(
        Left(Fields!ProductAlternateKey.Value, 6),
        Fields!ProductCodeWithoutColorAndSize.Value,
        Fields!Color.Value,
        "dsProductColors"
    ),
    ", "
)

The LookupSet call itself looks very similar to the Lookup, with the same four parameters.  I’ve used the Left function on the first parameter to apply the same logic to the ProductAlternateKey as we did with the ProductNumber.

However, there’s one important difference: the call of the Join function.  This is needed because the LookupSet is returning a set, or better, a VariantArray, not just a single value.  And an array cannot be visualized without first concatenating the values somehow.  With the Join, we can concatenate the different values, using a comma as separator.

And here’s the resulting report:

With the first two lookup functions covered there’s one more to go.

Just One More Lookup: The MultiLookup Function

Guess what crazy request the business people have come up with this time?!  The report should have a multi-value filter on region, and for each region selected, the top of the table should list the number of shops opened in the first year in those regions.  For example, if the first shop in France was opened in 1970 and in that same year there were two other shops opened in France, the report should state “France: 3 shop(s) opened in 1970”.

Ow, and that list should be located right under the main header so deciding to use a textbox outside of the table is not a good idea

Sounds like we can use the MultiLookup function for this request.  But let’s first set up the filter.

I’ve created a dataset called dsRegions, using the following query on the data warehouse:

select DST.SalesTerritoryAlternateKey,
    DST.SalesTerritoryCountry + ' - ' + DST.SalesTerritoryRegion as CountryRegion
from DimSalesTerritory DST
where DST.SalesTerritoryAlternateKey > 0

Then I’ve added a multi-value parameter called Regions with the Available Values coming from the dsRegions dataset.

This parameter can now be used in our main dataset.  Here’s the updated query:

select PROD.EnglishProductName, PROD.ProductAlternateKey, PROD.ListPrice,
    PSC.EnglishProductSubcategoryName, PC.EnglishProductCategoryName,
    S.OrderQuantity, S.SalesAmount
from FactInternetSales S
inner join DimProduct PROD on S.ProductKey = PROD.ProductKey
inner join DimProductSubcategory PSC
    on PROD.ProductSubcategoryKey = PSC.ProductSubcategoryKey
inner join DimProductCategory PC on PSC.ProductCategoryKey = PC.ProductCategoryKey
inner join DimSalesTerritory DST on S.SalesTerritoryKey = DST.SalesTerritoryKey
where DST.SalesTerritoryAlternateKey in (@Regions)

The only difference with the previous query are the two last lines: we add DimSalesTerritory to the joins and filter it on SalesTerritoryAlternateKey.

Don’t forget to set up the parameter.

With the filter implemented, let’s get started on that extra lookup. 

First we need to add the dataset containing the data that we need.  I’ve created a dataset called dsShopsOpenedInFirstYear, using the following query on the relational database:

with ShopOpened as
(
    select T.TerritoryID, T.Name Territory, S.Name ShopName,
        S.[Demographics].value('declare default element namespace "http://schemas.microsoft.com/sqlserver/2004/07/adventure-works/StoreSurvey";
        (/StoreSurvey/YearOpened)[1]', 'integer') AS [YearOpened]
    from Sales.Store S
    inner join Sales.SalesPerson SP on S.SalesPersonID = SP.BusinessEntityID
    inner join Sales.SalesTerritory T on SP.TerritoryID = T.TerritoryID
),
FirstShopOpened as
(
    select MIN(YearOpened) YearOpened, TerritoryID
    from ShopOpened
    group by TerritoryID
)
select SO.TerritoryID,
    SO.Territory + ': ' + CAST(COUNT(*) as varchar(100)) +
    ' shop(s) opened in ' + CAST(SO.YearOpened as char(4)) as ShopString
from FirstShopOpened FSO
inner join ShopOpened SO on SO.TerritoryID = FSO.TerritoryID
    and SO.YearOpened = FSO.YearOpened
group by SO.TerritoryID, SO.Territory, SO.YearOpened

This query uses a couple of Common Table Expressions to get to the result as we need it.  The first CTE, ShopOpened, creates a list of all shops with their territory and the opening year.  The second CTE, FirstShopOpened uses the ShopOpened CTE to retrieve the first opening year for each territory.

And finally the main query uses both CTEs to create the following result:

For each territory we’ve constructed a string that shows how many shops were opened in the first year of that region, and in what year it happened.  Coincidentally all regions had shops opened in 1970.

The TerritoryID corresponds with the SalesTerritoryAlternateKey, which is the value of our Regions parameter.

I’ve added an extra row under the top row in the table data region, and I’m using the following expression in that row:

=Join(
    MultiLookup(
        Parameters!Regions.Value,
        Fields!TerritoryID.Value,
        Fields!ShopString.Value,
        "dsShopsOpenedInFirstYear"
    ),
    "<br>"
)

The MultiLookup takes four parameters, just like the two previous lookup functions.  They are all the same, except for the first one.  It may not be very obvious in the example here, but the Parameters!Regions.Value is in fact not just a single value.  It’s an array because we’ve set up the parameter as being multi-valued.

And that’s exactly what the MultiLookup function requires.  Here’s the description for that first parameter, as stated in the Books Online:

(VariantArray) An expression that is evaluated in the current scope and that specifies the set of names or keys to look up. For example, for a multivalue parameter, =Parameters!IDs.value.

Just like the LookupSet function, MultiLookup returns a VariantArray, so we use the Join function to concatenate the values.

Interesting to note here is that I’m adding the break HTML tag as separator.  I want the result of the expression to be treated as HTML, so that each value retrieved ends up at a new line in the textbox.  To get this to work as expected, you need to tell the Placeholder that the resulting value should be treated as HTML:

Everything is now set up to have another report Preview.  The following screenshot shows the report with the data filtered on Canada, France and Australia:

Seems to be working fine, doesn’t it?

Okay, that’s it for now, have fun looking up that data!

Valentino.

References

BOL2008R2: Lookup Function

BOL2008R2: LookupSet Function

BOL2008R2: MultiLookup Function

What Does Microsoft Do With Those Memory Dumps?

The first one is written by Adam W. Saxton, a member of the Microsoft Customer Service and Support (CSS) SQL Server Escalation Services team.

The subject of the post is an issue that developers of Reporting Services reports may come across: “InvalidReportParameterException with Data Driven Subscription”.  The report complains about an invalid parameter while the parameters seem to be okay, visually.  Then the author goes on to describe the actual issue: trailing spaces!  If you’ve been doing BI for a while, this is a quite common issue.  Adam also shows the difference between the LEN() and the DATALENGTH() functions.

But that’s not the reason that I’m mentioning that article here.  The best part starts following the Summary chapter, and is entitled Techie Details.  In that extra chapter he shows how the CSS team uses those crash memory dumps which I’m sure you’ve all seen now and then. 

I won’t give you any details about that, just have a look at the article.  If you’re a developer, there’s some very valuable information there!

I am definitely looking forward to seeing his pre-conference session at the SQL PASS European Conference in Germany this year: Tackling Top Reporting Services Issues!

Some Crazy Code Samples

The second article that I’d like to mention here is written by Phil Factor, a regular at the Simple-Talk site.

This article is called Laying out SQL Code and mentions some database naming conventions and T-SQL coding layout, as the title already implies.  Even if you’re not interested in that (although as a serious developer you should be!!), the article is worth the effort of reading just for its code samples.

Here’s my favorite one:

CREATE TABLE "╚╦╩╗" ( "└┬┴┐" nvarchar(10))
DECLARE @ nvarchar(10)  set @='═'
INSERT  INTO "╚╦╩╗"
        ( "└┬┴┐" )
        SELECT  replicate(@,5)

SELECT  *
FROM    "╚╦╩╗"

And just to prove to you that this really is valid code, here’s the result:

So, how about that database for that plumbing company?

BTW: when running that code without paying attention to the details (such as what DB your SSMS is connected to), you may end up with something like this:

So you may want to clean up after running the query using this statement:

drop table "╚╦╩╗"

Have fun!

This article is aimed at report developers who are used to develop reports using relational databases and have gotten a first-time assignment to develop reports on OLAP cubes.

It demonstrates how to build a report using SQL Server Reporting Services 2008 with data coming from an OLAP cube running on SQL Server Analysis Services 2008.

The OLAP database used in the article is called “Adventure Works DW 2008”, available for download at CodePlex.

If you’re fairly new to Reporting Services (aka SSRS) and you find that this article is going a bit too fast, I’d like to point you to my other article which explains how to build a report that’s retrieving data using regular stored procedures.

OLAP <> OLTP

When people are talking about databases, what they are usually referring to are “regular” relational OLTP databases.  OLTP stands for Online Transaction Processing.  As the name implies, these types of databases are built to handle many simultaneous transactions (consisting of actions such as inserts, updates, deletes) in real-time.  I’m sure you’re familiar with these types of database so I won’t go further into them.

OLAP (Online Analytical Processing) on the other hand is a totally different story.  OLAP cubes are built to answer multi-dimensional analytical queries as fast as possible.  For that purpose, what you can find in such a database are measures (these are the numbers) stored in cubes, and dimensions which allow filtering the measures.  This filtering is often referred to as slicing and dicing.  Furthermore, OLAP cubes contain pre-aggregated data, again to be able to answer queries as fast as possible.

Let’s make this clear with an example.  Imagine the following request:

“Give me the sum of all sales of product X for period Y in country Z.”

Three dimensions can be recognized in that request: “product X” is found in the Product dimension, “period Y” in the Date dimension and “country Z” in the Geography dimension.  (I’ve used the actual dimension names as they are called in the Adventure Works OLAP database.)

Each dimension consists of attributes and attribute hierarchies and it’s those attributes that you’re actually referring to when building an MDX query.  MDX stands for Multidimensional Expressions and that is the language used to query an OLAP database, just like you use SQL to query a relational database.

Looking at our example, what we need is for the Product attribute in the Product dimension to be equal to X.  An attribute in a dimension can also be written as [Dimension].[Attribute], thus we also want [Date].[Date] to be equal to Y and [Geography].[Country] equal to Z.

As for the measure part, that’s what “the sum of all sales” is referring to.  When looking at the measures available in the Adventure Works cube, one of the measures that would fulfill the request is the Reseller Sales Amount in the Reseller Sales measure group.  The Analysis Services engine searches the cube and retrieves the aggregated number for [Measures].[Reseller Sales Amount] available at the intersection of [Product].[Product] X, [Date].[Date] Y and [Geography].[Country] Z.

OLAP cubes are usually, although not necessarily, build on top of a data warehouse.  In SQL Server, a data warehouse is still a relational database, unlike an OLAP cube, but the table structure is different from an OLTP database.  A data warehouse contains tables that represent dimensions and other tables that contain the facts.  The facts are the numbers, so the measures that were mentioned earlier.  This is called a dimensional model.  Dimensional modeling was invented by Ralph Kimball, one of the pioneers in data warehousing.  For completeness I’d like to mention that another data warehousing approach was described by Bill Inmon.  I’ll leave it up to you to do some research on both approaches and decide for yourself which one you prefer, possibly even a mix of both.

As far as the “Adventure Works DW 2008” OLAP database is concerned, it’s built on top of the AdventureWorksDW2008 dimensional database.

Okay, I believe this theoretical explanation was sufficient for now, let’s start with the report!

Your First Report

Business Requirements

You’ve gotten the assignment to create a report that shows the reseller sales numbers by region.  The highest level to be shown is Country, with drilldown through State/Province to City.

Creating The Shared Data Source

Just like when building reports on OLTP databases, we’re not going anywhere without a Data Source.  I’m going to create a Shared Data Source called OLAP_AdventureWorks.rds:

The Type that we need is Microsoft SQL Server Analysis Services, which is the SQL Server service that’s running the OLAP databases.  Furthermore I’ve selected the “Adventure Works DW 2008” database.

There’s no need to type the database name yourself.  After you’ve provided sufficient credentials in the Credentials page, you can just select it from the dropdown in the Connection Properties screen.  This screen is opened by clicking that Edit button on the Shared Data Source Properties window.

Your First OLAP Dataset

I’ve created a new report called FirstOLAPReport.rdl.  In that report I’ve specified that I’ll be using the Shared Data Source created earlier.  This source is known as srcAdventureWorksOLAP in my report.

Next step is to create the dataset.  I’m calling it dsResellerSalesByRegion.  As this is our first OLAP report, we’re not going to write the MDX ourselves but we will use the Query Designer which is opened by clicking the button that has the words Query Designer printed on them, how difficult can that be?!

The BIDS knows that it should open the MDX Query Designer because our data source is connecting to an Analysis Services server.  All we need to do now is to drag the measures and dimension attributes that we require into the area marked with “Drag levels or measures here to add to the query.”.

Let’s start by dragging our measures into that area.  We need two measures, both located in the Reseller Sales measure group.  They are called Reseller Order Quantity and Reseller Sales Amount.  Following screenshot shows the situation after the first measure has been added.  The second measure was being dragged into it as well.  When dragging items into the area, a vertical blue line appears to indicate where the item can be added.

Next I’m going to drag the Geography hierarchy, located in the Geography dimension, into the design area.

Now we’ve got all the data we need for our report.

As you have noticed, the Query Designer automatically executes the query each time it gets modified when you’re dragging an item into the design area.  If you don’t want this behaviour, it can be switched off by clicking the Auto Execute button in the toolbar (indicated by a red 1 in the screenshot below).

Another interesting button is the Design Mode button (indicated by a green 2).  This one allows you to toggle between the graphical designer and the text editor.  By clicking it you can see the actual MDX query that the designer has prepared for you.

As you can see, the query is nicely formatted using capitals for the keywords and so on.  Well, no, actually it’s the worst editor around!  No syntax coloring, no multi-line formatting, nothing.  So if you are going to take a close look at the query, I recommend you to use the Management Studio.  Connect to your Analysis Services server, locate your database and right-click it in the Object Explorer.  Then choose New Query > MDX and paste the query into that new window.  You’ll still need to manually break it down into different lines but at least you get syntax coloring.  Furthermore, if you’re going to make manual modifications to it, you’ve got some command completion and error indicators as well.

Please take into account that once you’ve made manual changes to your query, you cannot switch back to the graphical designer.  Well, you can, but you will lose all manual modifications.  Don’t worry about doing it accidentally though, a nice pop-up will warn you:

Something else that you’ll also notice is that the results displayed in the Query Designer and those displayed in the Management Studio are not exactly the same.  That’s because both environments interpret the results differently.  Remember, you’re not retrieving two-dimensional row/column data like with a SQL query.  You’re retrieving multi-dimensional data!

If you take a closer look at the query that we’ve produced above, it’s similar to this:

SELECT something ON COLUMNS,
    something_else ON ROWS
FROM [Adventure Works]

Displaying The Result Set

As a reference, these are the fields available in our dataset:

Without going into too much detail – there’s no difference compared to reporting off a relational database – I’ve set up a table with three grouping levels on the rows.  I’ve also added some makeup like background colors and font modifications.

As shown in following screenshot, the highest-level group is Country, followed by State_Province and City to conclude, just as specified in the requirements mentioned at the start of this chapter.

Rendering the report in preview gives us something like this:

What is still missing at this point is decent formatting for those numbers!  And here’s where we can take advantage of the fact that we’re retrieving data from an OLAP cube.  A cube developer has the possibility to define the format for the measures in the cube itself.  Doing that ensures that the same formatting is applied no matter what OLAP client tool is used.  Any client that supports this way of formatting will show the numbers using the same format.

As you’ve seen in that last screenshot, there’s no formatting applied at all.  Does this mean that there was no format defined in the cube?  Let’s find out!

A Little Walk Into The Analysis Project

We are going to open up the Analysis Services project that contains the cube definition.  If you don’t have any experience with SSAS, don’t worry!  We will just have a look at a couple of properties and that’s it, plus I’ll explain each step as needed.  In case you’ve forgotten where the sources are located, this is the default location: C:\Program Files\Microsoft SQL Server\100\Tools\Samples\AdventureWorks Analysis Services Project\.  I’m opening the project located under the \enterprise subfolder by double-clicking the Adventure Works.sln file.

Once the project is loaded into the BIDS, locate and open the Adventure Works.cube in the Solution Explorer.  You can find it in the Cubes folder of the Adventure Works DW project.

By default it will open the cube Design showing the first page called Cube Structure.  At the top-left, we’ve got the Measures pane.  The measures are shown in measure groups.  Open the group called Reseller Sales.  Now locate the measure called Reseller Sales Amount and select it.

Now that we’ve selected one of the measures that we are retrieving in our report, have a look at the Properties window.  In case it’s not open yet you can right-click the measure and select Properties.  The property that we’re interested in is called FormatString.

The cube developer has specified that this measure should be shown as being a Currency.

Now that you’re in the cube, have a look at the properties for our other measure, the Reseller Order Quantity.  This one is being formatted as #,#.

The FormattedValue Field Property

So why are we not seeing those formats in our report?  Because by default they are not applied in an SSRS report!  When dragging fields from the Report Data window onto the design area, what the BIDS is retrieving is the Value property of the field.  However, there’s also a property called FormattedValue.

(You may want to make a copy of your report before applying the following changes.)

Now, change the six table cells that are showing the numbers (so including the ones showing the totals) to retrieve the FormattedValue property instead of the Value property.  The expression for the totals of the Reseller Sales Amount looks like this:

=Sum(Fields!Reseller_Sales_Amount.FormattedValue)

Once you’ve done that, have a look at the Preview:

That doesn’t look right, does it?  We’ve lost our numbers!

Now hit the Refresh button:

This time we’ve got some numbers:

But we’ve also got some errors for free!  Looking at the Output window we get some extra details on the reason for the error.  Here’s one of them:

[rsAggregateOfNonNumericData] The Value expression for the textrun ‘Reseller_Order_Quantity1.Paragraphs[0].TextRuns[0]’ uses a numeric aggregate function on data that is not numeric.  Numeric aggregate functions (Sum, Avg, StDev, Var, StDevP, and VarP) can only aggregate numeric data.

In short, what it says is that our data is not numeric.  And this poses an issue when it tries to apply the SUM() aggregate function.  Right, as our data now contains formatting, it became a string instead of a number, and strings can’t be added together using SUM().

So that’s not a good way to apply the formatting, not in this case anyway.  Luckily there’s another method to do that.

But first, undo those last changes and replace the FormattedValue with the Value property.

(Or switch back to the original report if you took a copy earlier.)

The Cell Properties

What exactly is our MDX query doing?  I’m taking a closer look at it by taking it from the Dataset Properties window and pasting it into a MDX query window in the Management Studio:

SELECT
NON EMPTY { [Measures].[Reseller Sales Amount], [Measures].[Reseller Order Quantity] }
ON COLUMNS,
NON EMPTY { ([Geography].[Geography].[Postal Code].ALLMEMBERS ) }
DIMENSION PROPERTIES MEMBER_CAPTION, MEMBER_UNIQUE_NAME
ON ROWS
FROM [Adventure Works]
CELL PROPERTIES VALUE, BACK_COLOR, FORE_COLOR, FORMATTED_VALUE,
FORMAT_STRING, FONT_NAME, FONT_SIZE, FONT_FLAGS

Besides retrieving the requested measures and dimension attributes, it’s retrieving several Cell Properties, including FORMATTED_VALUE and FORMAT_STRING.  I believe that the first one rings a bell by now.  What we’re going to do is to retrieve the second one and apply it as Format property for our numeric table cells.

In the report’s Design, select one of the table cells containing a number.  In the Properties window, one of the properties is called Format.  Click to select it, then in the dropdown choose Expression….  For each of the six numeric cells, create an expression similar to the following:

=Fields!Reseller_Order_Quantity("FORMAT_STRING")

The example above tells the BIDS to retrieve the FORMAT_STRING cell property from the Reseller_Order_Quantity field.

Tip: you don’t need to open up the Expression builder for each of the six cells.  You can just copy/paste the string from the Format field.  Just ensure that you’re retrieving the format from the same field as the one that the cell is displaying.

Now let’s have a look at the Preview again:

Hmm,  the quantities are fine now, but the currencies are not!  So, let’s try out yet another method for those cells.

For the three cells containing a currency measure, remove the Format property – it’s not working anyway!

Next, change the expression that’s retrieving the Value property to something similar as this one:

=Format(Sum(Fields!Reseller_Sales_Amount.Value),
    Fields!Reseller_Sales_Amount("FORMAT_STRING"))

This expression applies the value of the FORMAT_STRING property using the Format() function.  In this particular case it’s the expression used to produce the Reseller Sales Amount total.

Having modified all three currency cells, here’s another Preview look:

That certainly looks better doesn’t it?!

Okay, to conclude, let’s activate drilldown by setting the subgroup levels to a collapsed state by default.

I will not go into full detail on this.  To start, make sure that the cells that are going to contain the +/- toggle have gotten a decent name, such as txtCountry for the cell that shows the Country name.  Then edit the properties of the subgroups by setting Visibility to Hide.  Also, activate the Display can be toggled by this report item checkbox and select the textbox showing the label one level higher.  Shown below is how to configure the group on State_Province.

Let’s have another look at the report Preview:

By default all nodes were collapsed.  I’ve expanded a couple of them just to show that it’s all working.

The InitialToggleState Property

Okay, I will not let you go just yet.  To really conclude I’ll let you in on a little feature related to the drilldown.  Open up the group properties for the State_Province group and set the initial visibility to Show (leave the “Display can be toggled by this report item” checked!).  Then checkout Preview:

Wow, that’s weird, the country level is expanded and yet there’s a plus icon in front of the country’s name.  Clicking it will collapse the states and change the icon to minus.  If that isn’t mixed up then I don’t know what is!

Well, the solution to this problem is simple.  Select the textbox showing the country name and locate the InitialToggleState property.  By default this is set to False, which means collapsed or in other words, False shows the plus icon.  Change it to True and now your initial state icon will be a minus!

Conclusion

With this article I believe to have shown you how to get started with reporting off an OLAP cube while throwing in a couple of tips in the process.

Have a look at another article that I wrote earlier, it explains an issue which you may run into when taking OLAP reporting a step further: SSRS and MDX: Detecting Missing Fields

Happy Reporting!

Valentino.

References

BOL 2008: The Basic MDX Query

BOL 2008: Using Cell Properties (MDX)

MDX: Retrieving Cell Properties by Greg Galloway

In a previous article I announced that I would write a sequel covering how to pass multiple-value parameters from a SQL Server Reporting Services report to a stored procedure.  So that’s what I will be writing about in this article.

As usual, I will be using the AdventureWorks2008 sample database (running on SQL Server 2008 SP1), downloadable from CodePlex.

The examples in this article, Part 2, are building further on the result achieved when following the steps described in Part 1, so please refer to the previous article if needed.

Passing Multi-Value Parameter To Stored Procedure

As we’ve already seen in Part 1, parameters can be passed from a Reporting Services report to a stored procedure.  The parameter that was used was just a simple, single-valued parameter.  However, a report parameter can be defined as being multi-value.  Let’s set one up!

Our report currently shows a list of employees who were hired after the selected hire date.  One of the columns being shown is the department in which they’re active.  We will modify the report so that it’s possible to filter the data on department – only the selected departments are to be retrieved from the database.

Creating A Multi-Value Report Parameter

The first step is to create a new report parameter, so right-click the Parameters node in the Report Data pane and select Add Parameter….

I’m calling my parameter Department, and I want it to be of type Integer.  In case you’re wondering why Integer, it will become clear very soon.  I have also checked the Allow multiple values checkbox:

We want to make the parameter user-friendly so that the user sees a list of departments and can just select those that he needs.  That means the parameter needs to be populated with that list of departments.  To be able to do that, we first need to create a new dataset that retrieves the list of departments.

So for now, close the Report Parameter Properties screen and use the following query to create a dataset called dsDepartmentList:

select D.DepartmentID, D.Name as DepartmentName
from HumanResources.Department D
order by D.Name asc

This is what our query returns:

Once the dataset is created, open up the properties of the Department Report Parameter created just before and select the Available Values page.

On that page, select the Get values from a query radio button, choose dsDepartmentList in the Dataset dropdown, select DepartmentID as Value field and DepartmentName as Label field.  The Label field is what the user sees while the Value field is what Reporting Services will use as value.  After all, we want to pass the IDs of the selected departments to our stored procedure, not the department names.  And we want the user to see the department names, not their ID.

By default, no values are selected.  To make it a bit more user-friendly, let’s select all departments by default when the report first loads.  This is done on the Default Values page.

Select the Get values from a query radio button, dsDepartmentList as Dataset and DepartmentID as Value field.

That’s it, the multi-value report parameter is created!  Of course, at this moment it doesn’t have any effect on the report’s content yet (switch to Preview if you don’t believe me and have a look).  We’ll get to that next.

Discover What Is Being Passed To The Stored Procedure

To be able to handle the values passed into our stored procedure, let’s first find out what exactly our report is passing into it.  We’ll do this by temporarily creating a new stored proc that will just accept the parameter values and return them.

This is what our test SP looks like:

CREATE PROCEDURE MultiValueParam
    @MyParam varchar(1000)
AS
BEGIN
    SELECT @MyParam as TheParameterReturned;
END

It accepts one parameter and returns it in a field called TheParameterReturned.

Set up a new dataset that calls this SP, called dsMultiValueParamTest.  I’m sure you know how to do this by now

When creating the dataset, on the Parameters page, select the new parameter [@Department] that we created earlier:

To see what the field contains, drag it from the Report Data pane onto the report canvas, above the table that was created in Part 1.  Enlarge the textbox a bit and activate the Preview tab.  Select a hire date (doesn’t matter which one) and click the View Report button.  As we’ve set up the report to select all departments by default, we don’t need to select them manually.  But of course if you want you can have a look in the Departments dropdown to check if they are actually selected.  This is the result after clicking the View Report button:

If you compare that list of numbers with the result that our dsDepartmentList query returns, you’ll see that these are the values from the DepartmentID field in exactly the same order as in the query’s result.  And separated by commas.  So in other words: it’s a comma-separated string of selected values.

Wrong Way To Implement The Parameter

Now that we know what exactly the multi-value parameter passes to a stored procedure, let’s modify our main procedure by adding the extra parameter to it.

Here’s the modified procedure:

ALTER PROCEDURE GetEmployeeData
    @HireDate date,
    @DepartmentList varchar(1000)
AS
BEGIN
    SELECT E.NationalIDNumber, E.JobTitle, E.BirthDate, E.MaritalStatus, E.Gender,
        E.HireDate, E.SalariedFlag, E.VacationHours, E.SickLeaveHours,
        D.GroupName as DepartmentGroupName, D.Name as DepartmentName,
        P.FirstName, P.MiddleName, P.LastName
    FROM HumanResources.Employee E
    INNER JOIN HumanResources.EmployeeDepartmentHistory EDH
        ON EDH.BusinessEntityID = E.BusinessEntityID
        AND EDH.EndDate IS NULL -- current active department does not have EndDate filled in
    INNER JOIN HumanResources.Department D
        ON D.DepartmentID = EDH.DepartmentID
    INNER JOIN Person.Person P
        ON P.BusinessEntityID = E.BusinessEntityID
    WHERE E.HireDate > @HireDate
        AND D.DepartmentID IN (@DepartmentList);
END

Since our parameter is a comma-separated list of our values, I’ve used the IN operator to filter on only the selected values.

Next we need to add the extra parameter to the dsEmployeeData dataset.  Double-click it in the Report Data pane to get its properties and click the Refresh Fields button to have it add the new parameter to the list.  Then switch to the Parameters page and select the [@DepartmentList] parameter as Parameter Value for the newly-added @DepartmentList parameter.

Close the properties popup and run the report by activating the Preview tab.

Oh no, an error!  More precisely this one (I will only mention the last line):

Conversion failed when converting the varchar value ‘12,1,16,14,10,9,11,4,7,8,5,13,6,3,15,2’ to data type smallint.

This error comes from our stored procedure.  It complains that it cannot convert the list of values from a string to a smallint.  Weird isn’t it?  Well, maybe not.  Let’s have a look at what’s going on.

The following query would work perfectly:

SELECT E.NationalIDNumber, E.JobTitle, E.BirthDate, E.MaritalStatus, E.Gender,
    E.HireDate, E.SalariedFlag, E.VacationHours, E.SickLeaveHours,
    D.GroupName as DepartmentGroupName, D.Name as DepartmentName,
    P.FirstName, P.MiddleName, P.LastName
FROM HumanResources.Employee E
INNER JOIN HumanResources.EmployeeDepartmentHistory EDH
    ON EDH.BusinessEntityID = E.BusinessEntityID
    AND EDH.EndDate IS NULL -- current active department does not have EndDate filled in
INNER JOIN HumanResources.Department D
    ON D.DepartmentID = EDH.DepartmentID
INNER JOIN Person.Person P
    ON P.BusinessEntityID = E.BusinessEntityID
WHERE D.DepartmentID IN (12,1,16,14,10,9,11,4,7,8,5,13,6,3,15,2); 

But that is not what is being executed by our SP!  In the query above, we are passing a list of numbers to the IN operator.  But our SP accepts a varchar, a string.  Sure, the report parameter passes a list of numbers, but they are stored in a string!  An equivalent query for what our SP actually executes is the following:

SELECT E.NationalIDNumber, E.JobTitle, E.BirthDate, E.MaritalStatus, E.Gender,
    E.HireDate, E.SalariedFlag, E.VacationHours, E.SickLeaveHours,
    D.GroupName as DepartmentGroupName, D.Name as DepartmentName,
    P.FirstName, P.MiddleName, P.LastName
FROM HumanResources.Employee E
INNER JOIN HumanResources.EmployeeDepartmentHistory EDH
    ON EDH.BusinessEntityID = E.BusinessEntityID
    AND EDH.EndDate IS NULL -- current active department does not have EndDate filled in
INNER JOIN HumanResources.Department D
    ON D.DepartmentID = EDH.DepartmentID
INNER JOIN Person.Person P
    ON P.BusinessEntityID = E.BusinessEntityID
WHERE D.DepartmentID IN ('12,1,16,14,10,9,11,4,7,8,5,13,6,3,15,2'); 

When executing that in the Management Studio, it will throw this error:

Msg 245, Level 16, State 1, Line 1

Conversion failed when converting the varchar value ‘12,1,16,14,10,9,11,4,7,8,5,13,6,3,15,2′ to data type smallint.

Doesn’t that look familiar?!

The reason for this error is the following.  The DepartmentID field is of type smallint.  Therefore SQL Server tries to convert the list of values to smallint.  In the first SELECT statement, each value gets converted to smallint and all works fine.  In the second SELECT, SQL Server sees just one value, a varchar(1000), and tries to convert that to a smallint.  It fails because the value that the string contains is not convertible to smallint.  If the string would contain only one value, it would actually work.

You can try it out by replacing the last line with this:

WHERE D.DepartmentID IN ('12'); 

Right Way To Implement The Parameter

We’ve seen that our first implementation of using the IN operator is not a good idea.  So we need to find another way to get this stored procedure working.

Note: it would actually be possible to use the previous method in combination with dynamic SQL but I’m not going to apply that technique here.  In case you are interested in that method, just construct a long string that contains the whole query as it is in the working SELECT statement above.  For more info on dynamic SQL I’d like to point you to this excellent article by SQL Server MVP Erland Sommarskog: The Curse and Blessings of Dynamic SQL.

The IN operator can take a subquery.  So now we need to find a way to “select” the values out of our comma-separated string of values.  I am not going to re-invent the wheel and use a function that’s mentioned in another great article by Erland Sommarskog.  The article is called Arrays and Lists in SQL Server 2005 but is also applicable to 2008 and mentions a function called iter$simple_intlist_to_tbl.

For this article’s readability purposes I’ve renamed the function to list_to_tbl.  Here’s the code to create it:

-- from http://www.sommarskog.se/arrays-in-sql-2005.html
-- original name: iter$simple_intlist_to_tbl
CREATE FUNCTION list_to_tbl (@list nvarchar(MAX))
   RETURNS @tbl TABLE (number int NOT NULL) AS
BEGIN
   DECLARE @pos        int,
           @nextpos    int,
           @valuelen   int 

   SELECT @pos = 0, @nextpos = 1 

   WHILE @nextpos > 0
   BEGIN
      SELECT @nextpos = charindex(',', @list, @pos + 1)
      SELECT @valuelen = CASE WHEN @nextpos > 0
                              THEN @nextpos
                              ELSE len(@list) + 1
                         END - @pos - 1
      INSERT @tbl (number)
         VALUES (convert(int, substring(@list, @pos + 1, @valuelen)))
      SELECT @pos = @nextpos
   END
  RETURN
END

It takes a list of comma-delimited integers and returns a resultset containing integers, just what we need!

When we implement this in our main procedure, this is what it looks like:

ALTER PROCEDURE GetEmployeeData
    @HireDate date,
    @DepartmentList varchar(1000)
AS
BEGIN
    SELECT E.NationalIDNumber, E.JobTitle, E.BirthDate, E.MaritalStatus, E.Gender,
        E.HireDate, E.SalariedFlag, E.VacationHours, E.SickLeaveHours,
        D.GroupName as DepartmentGroupName, D.Name as DepartmentName,
        P.FirstName, P.MiddleName, P.LastName
    FROM HumanResources.Employee E
    INNER JOIN HumanResources.EmployeeDepartmentHistory EDH
        ON EDH.BusinessEntityID = E.BusinessEntityID
        AND EDH.EndDate IS NULL -- current active department does not have EndDate filled in
    INNER JOIN HumanResources.Department D
        ON D.DepartmentID = EDH.DepartmentID
    INNER JOIN Person.Person P
        ON P.BusinessEntityID = E.BusinessEntityID
    WHERE E.HireDate > @HireDate
        AND D.DepartmentID IN (select * from list_to_tbl(@DepartmentList));
END

And indeed, if we now run our report again, it works perfectly!

Note: for another great reference on how to deal with a delimited list as Stored Proc parameter, I’d like to point you to the following article by colleague Expert and SQL Server MVP angelIII: http://www.experts-exchange.com/articles/Database/Miscellaneous/delimited-list-as-parameter-what-are-the-options.html

Displaying The Filter On The Report

Another best practice as far as report readability goes is that it should be clear on your report what data has been filtered.  As the multi-value parameter is on focus here, I’ll demonstrate how you can show the selected values on your report.

In fact, it’s not really the parameter’s values that we are interested in now (those are DepartmentIDs, remember?).  No, it’s the labels.  And here’s how to get to them.  Add a new textbox above the main report table.  Make it the same width as the table and right-click it to add an Expression.  Enter the following expression:

It uses the Join function to join all members of the Label collection together into one string, using comma and space as the value separator.  This is what it looks like on the report:

In case you would like to see the selected departments under each other instead of in a long string, that’s also quite easy to achieve.  The expression is based on Visual Basic, and in Visual Basic there’s a constant called vbCrLf – Visual Basic carriage-return line-feed.  Adapt the expression to the following and the values will be shown in a list instead of a long string:

Conclusion

With this article I believe I’ve demonstrated that it is possible to pass multi-value parameters from a SQL Server Reporting Services report to a stored procedure, while applying some best practices such as giving the users a nice list of values to select from. 

Happy reporting, thank you for reading my article, and should you feel like it: post a comment!

Valentino.

References

BOL 2008: the IN operator

The Curse and Blessings of Dynamic SQL by Erland Sommarskog, SQL Server MVP

Arrays and Lists in SQL Server 2005 by Erland Sommarskog, SQL Server MVP

BOL 2008: Expression Examples (Reporting Services)

delimited list as parameter, what are the options? by angelIII, SQL Server MVP

The first step of creating a SQL Server Reporting Services (SSRS) report involves setting up a connection to the data source and programming a dataset to retrieve data from that data source.  The dataset can use a SELECT query, which is the most common way of retrieving data and one that you’re probably already familiar with.  But it can also use a Stored Procedure (aka stored proc or SP).

The purpose of this article is to demonstrate how data can be retrieved from a SQL Server database through Stored Procedures defined in that same database, and then displayed in a SQL Server 2008 Reporting Services report.

I’ll be using the AdventureWorks2008 sample database available for download at CodePlex.

What Are Stored Procedures?

There are actually different types of stored procedure in the context of SQL Server.  The type that I am using in this article is called a “Transact-SQL Stored Procedure”.  According to the Books Online, this type of stored procedure is:

“A saved collection of Transact-SQL statements that can take and return user-supplied parameters.”

If you have experience using a regular programming language such as Visual Basic or C#, I’m sure this sounds familiar.  You can think of a stored procedure as a method that takes any number of parameters, depending on its definition, and that possibly returns a result, again depending on its definition.  Instead of being stored in a compiled .exe or .dll, it is stored in the database.

In this article I will be using some stored procedures that return a dataset as result.  How stored procedures are written is not the purpose of this article.  For that I’d like to refer you to this Books Online page: Implementing Stored Procedures.

Reasons For Using A Stored Procedure

There are several reasons why it is more interesting to use datasets based on stored procedures as opposed to SELECT statements.

Performance: stored procedures perform faster than SELECT statements.  The reason for this is because they are compiled when they’re created and their execution plan gets stored by SQL Server so that it can be reused for each procedure call.

Maintenance: when a database needs to undergo some changes to its schema, the changes can be handled in the stored procedures.  This makes it transparent for the reports that are using these stored procedures.  The reports will keep functioning as expected without any modifications to them.

Reuse: imagine a situation where several reports are reporting on the same set of data.  If you wouldn’t use stored procedures, you may have to repeat a possibly complex query in each report.  With stored procedures you just need to define the query in the stored procedure and then call it in each report’s dataset.

Security: in environments where DBAs are responsible for the SQL Server databases, the report developers will possibly not get sufficient rights to retrieve data from the tables directly.  One of the ways to prevent this is to give them access to a bunch of stored procedures and views instead.

Simple Procedure Call

Okay, enough theory, time to show you how it’s done!

Setting Up The Stored Procedure

Our first procedure queries the AdventureWorks database to return a list of employees with their corresponding department.  Here’s the code for the SP:

CREATE PROCEDURE GetEmployeeData
AS
BEGIN
    SELECT E.NationalIDNumber, E.JobTitle, E.BirthDate, E.MaritalStatus, E.Gender,
        E.HireDate, E.SalariedFlag, E.VacationHours, E.SickLeaveHours,
        D.GroupName as DepartmentGroupName, D.Name as DepartmentName,
        P.FirstName, P.MiddleName, P.LastName
    FROM HumanResources.Employee E
    INNER JOIN HumanResources.EmployeeDepartmentHistory EDH
        ON EDH.BusinessEntityID = E.BusinessEntityID
        AND EDH.EndDate IS NULL -- current active department does not have EndDate filled in
    INNER JOIN HumanResources.Department D
        ON D.DepartmentID = EDH.DepartmentID
    INNER JOIN Person.Person P
        ON P.BusinessEntityID = E.BusinessEntityID;
END

Creating The Report

Creating A Shared Data Source

Creating The Data Source

Creating The Dataset

I’m calling the Dataset dsEmployeeData.  The Data Source edit box is already prefilled with the right data source because we’ve right-clicked the data source to which we want to add a dataset, how easy can it be?

To query a stored procedure from a dataset is really very straightforward.  All you need to do now is select the Stored Procedure radio button.  Doing that replaces the bottom part of the window.  Instead of an edit box that expects a query, we now get a simple dropdown where we need to select our SP.

Once you’ve done that, select the Fields page on the left.

As you can see, the list of fields has been pre-filled.  The BIDS queries the stored procedure’s metadata so we do not need to manually specify the fields returned by our SP, saving us quite some time!

Once you click OK to close the Dataset Properties window, you’ll see that the Report Data pane gets populated with our list of fields.

Show Me The Data

To prove that everything is working as expected, let’s set up a quick report using a Table.  From the Toolbox pane, drag a Table object onto the report canvas:

Next, from the Report Data pane, drag some fields into the cells in the Data part of the Table.  As we’re dealing with employee data, it would be interesting to see their names.  I’ve also added their job and department.

Resize the columns a bit so that everything will fit nicely, and color the Header cells different from the Data cells to easily distinguish them.

Now we’re ready to run the report, so click the Report’s Preview tab.

So, that was our first procedure.  Wasn’t too complicated, was it?  So, ready for another one?

Parameterized Procedure Call

This time we’ll make it a little more complicated.  As you know, stored procedures can take parameters.  And SSRS knows how to pass them into a stored proc.  So let’s do that!

Setting Up Stored Proc Version 2.0

The stored procedure shown below is based on our previous one.  Except now it takes one parameter: @HireDate.  The SP will only return employees that have been hired after given HireDate.

ALTER PROCEDURE GetEmployeeData
    @HireDate date
AS
BEGIN
    SELECT E.NationalIDNumber, E.JobTitle, E.BirthDate, E.MaritalStatus, E.Gender,
        E.HireDate, E.SalariedFlag, E.VacationHours, E.SickLeaveHours,
        D.GroupName as DepartmentGroupName, D.Name as DepartmentName,
        P.FirstName, P.MiddleName, P.LastName
    FROM HumanResources.Employee E
    INNER JOIN HumanResources.EmployeeDepartmentHistory EDH
        ON EDH.BusinessEntityID = E.BusinessEntityID
        AND EDH.EndDate IS NULL -- current active department does not have EndDate filled in
    INNER JOIN HumanResources.Department D
        ON D.DepartmentID = EDH.DepartmentID
    INNER JOIN Person.Person P
        ON P.BusinessEntityID = E.BusinessEntityID
    WHERE E.HireDate > @HireDate;
END

As the HireDate field in the HumanResources.Employee table is of type date, I chose to make the parameter that same data type.

Please note that the above script uses ALTER PROCEDURE instead of CREATE PROCEDURE.  This will only work if you’ve already created the previous procedure.  If not, just replace the word ALTER with CREATE.

Modify Report To Pass Parameter To Stored Procedure

The next step is to modify our existing Dataset so that it passes a date into our stored procedure.

Open up the Dataset’s properties by double-clicking it in the Report Data pane.  Then select the Parameters page:

As you can see, it is still empty.

Now switch to the Query page and click the Refresh Fields… button:

Then switch back to the Parameters page:

The parameter has been automatically added when we clicked the Refresh Fields… button!

The BIDS again used the stored proc’s metadata to do this.  No need for manual intervention.  For now, leave the Parameter Value box as it is, empty.  Click OK to close the properties window.

Clicking OK caused another action in our report!  If you open up the Parameters folder in the Report Data pane, you’ll see that it has gotten an item as well:

You can double-click the @HireDate parameter to get its properties:

The BIDS has created a report parameter and linked it to the parameter in our Dataset.  It automatically chooses the correct data type for the report parameter, Date/Time in this case.  (Unlike in T-SQL, there are no separate Date and Time data types in SSRS 2008.)

To confirm that the report parameter is linked to the parameter in the Dataset, close the Report Parameter Properties window and open up the Dataset Properties again, selecting the Parameters page:

The Parameter Value for our parameter has now gotten a value, more precisely it’s referring to the Report Parameter called @HireDate.  If you don’t believe that it is actually the report parameter (I admit, it looks similar to the parameter in the Dataset, except for the square brackets surrounding the report parameter’s name.), click the fx button to see the formula:

Indeed, it is referring to the parameter on the report.

Test The Changes

Now that the parameter has been set up, it’s time to test our report again.

As the report is now filtering on the HireDate, it would be interesting to actually show this field in the table.  Add an extra column and drag this field into the data cell.

Our newly added field’s type is datetime, but we’re only interested in the date part.  So we’ll set up a format code.  Select the HireDate data cell and locate the Format property in the Properties pane.  Enter a small d into it:

This instructs the BIDS to show the field using the “short date pattern”.  A list of possible codes is available on MSDN: Standard Date and Time Format Strings.  As you notice, SSRS is using the regular formatting strings as they are known in .NET.

Note also that the format used to display the data depends on the report’s Language property.  I’ll leave it at its default: en-US.

Right, time to have a look at the report.  Select the Preview tab.  You can now see the Hire Date parameter which is expecting a value.  You can either type a value or select it from the calendar which is shown when you click the button on the right of the textbox:

To be sure that you’re using the correct format for the date, I suggest to select a date using the control.  Then you can always modify it to whatever day you’d like to select.

For our test I know that some employees started before 2000 and others later, so I’ll select a date somewhere in the year 2000.

And indeed, our report shows only employees that started after our selected HireDate.

Conclusion

With this article I hope to have shown you that it’s fairly straightforward to report on data coming from stored procedures.

In case the above hasn’t fulfilled your appetite on this subject yet, watch out for part 2.  In that sequel I will build further on the example used in this article to show you how you can use multi-value parameters to filter your report’s data.

In the meantime: happy reporting, and thank you for reading my article!

References

BOL 2008 – How to: Create an Embedded or Shared Data Source

BOL 2008 – How to: Create a Dataset (Reporting Services)

BOL 2008 – How to: Refresh Fields for a Dataset

BOL 2008 – Implementing Stored Procedures

BOL 2008 – Data Sources Supported by Reporting Services

As usual, I will be using the AdventureWorks2008 database, available at CodePlex.  The chart itself will be implemented using SQL Server 2008 Reporting Services.

Retrieving The Data

The dataset in our report uses the following query:

select SWD.*, SWA.City, SWA.StateProvinceName,
    SWA.PostalCode, SWA.CountryRegionName, SWA.AddressType
from Sales.vStoreWithDemographics SWD
inner join Sales.vStoreWithAddresses SWA
    on SWA.BusinessEntityID = SWD.BusinessEntityID

This query illustrates a bad coding practice: never use “SELECT *”.  Ideally you should only retrieve the columns that you need for the report.  That will optimize performance when generating the report.  But that is not the goal of this article so I’ll leave the query as it is.

A Basic Pie Chart

To get started with our Pie Chart I have selected the third icon in the list of Shape charts.  This adds a regular 3D pie chart to the report.

To set up the chart I dragged AnnualSales from the Report Data pane into the “Drop data fields here” area and StateProvinceName into the “Drop category fields here”.

In case you don’t see the Report Data view (it has a tendency to disappear now and then), you can open it through the main menu: View > Report Data.

This is what our report looks like in Preview:

Wow, we’ve still got some work to do, this looks like a kids color book!  You wouldn’t say that this chart is showing the annual sales, would you?  There aren’t even any numbers on it!  Let’s get started on improving this.

Sorting The Numbers

A good implementation practice is to sort the slices from large to small.  If the slices are not sorted, it’s difficult to tell which state is performing better than another.  Just take a look at the previous image and compare the following two slices:

• the pie shown in grey at 12:00
• the pie shown in yellow at 03:00

Which one is the larger of the two?  Indeed, “I don’t know” is the right answer.

To implement the sorting you need to think about what you want to achieve.  What is it that we want to sort?  The states.  And these are shown as categories on the chart, so we should take a look at its properties.  As shown in the following screenshot, right-clicking on the [StateProvinceName] button gives a pop-up menu.  Select Category Group Properties.

Then we need to think about how we want the states to get sorted.  For that we should look at what is being shown as data of the chart.  In our case that is the sum of the AnnualSales field.

In the Category Group Properties, select the page called Sorting.  Clicking the Add button will add a line in the sorting options list.  Use the following expression for the “Sort by” field:

=Sum(Fields!AnnualSales.Value)

As we want to sort the largest values first, select “Z to A” for the Order dropdown.

Right, time to have another look at our report in Preview.

So, we went from a colorful mess to an ordered colorful mess.  Chaos has been reduced a bit, but this is still one difficult-to-read report.

On to the next improvement!

Limiting The Pies

As you have noticed, a pie chart is not suitable to show that many categories.  We need to find a way to reduce the slices.  One way to do that is by adding a filter.  Another way is to add the smallest slices together into one slice.  This can be interesting in cases where we want to use all the data but we’re only interested in the larger slices.  Luckily, this can be done using standard pie chart properties.

Click on the pie itself, this will select the Chart Series.  One way to tell if you’ve selected the correct part of the chart is by looking at the Properties pane.  Its selection should show something like “AnnualSales Chart Series”, where AnnualSales is the name of the chart series.  Another way to tell is by the small white selector bulbs: they should be surrounding the pie.

Now, among the properties of the Chart Series you will find a property group called CustomAttributes.  Open this one by clicking the plus icon in front of it.  Change the CollectedStyle property to SingleSlice.  This tells the chart that we want to group the smallest slices into one slice.

Other interesting properties here are CollectedThreshold and CollectedThresholdUsePercent.  I’ve put CollectedThreshold to 2 and CollectedThresholdUsePercent to True (which is its default).  This means that any slice smaller than 2 percent of the pie will be added into the “collected slice”.

More useful properties are CollectedLabel, that’s the text that is shown on the slice itself, and CollectedLegendText, the text shown in the legend.

The CollectedStyle property has another option besides the one I’ve shown, called CollectedPie.  Choosing that will generate a second pie next to the main one to represent all the small slices.  See the following screenshot for what it looks like.  In some cases this may be an interesting option but not in our example here.

The collected pie can also show labels by setting the CollectedChartShowLabels property to True, and the categories shown on the collected pie can be shown in the pie’s legend by setting CollectedChartShowLegend to True.

If you’d like the collected slice to jump out, there’s a property called CollectedSliceExploded.  Setting it to True will produce something like the following:

As you have noticed, the previous screenshots have started to show text on the slices.  This can be easily activated by right-clicking the pie and selecting the Show Data Labels menu item.

And the next screenshot shows what our chart currently looks like.

The small slices have been replaced by a really large one, and the text on the large slice is our customized version.  The other slices are showing some rather large numbers, so we still have some work to do.

Displaying Percentages

Let’s customize the label shown on the slices.  As the numbers are really large, I recommend to divide them by 1,000.  As long as it’s clearly mentioned on the report, it will make everything more readable.

Furthermore I’ll show you how to use built-in chart keywords (only available to ToolTips, custom legend text, and data point label properties), such as #PERCENT.

Right-click on one of the data labels and select Series Label Properties.

Click the expression (fx) button on the General page and enter the following expression:

=FormatCurrency(Sum(Fields!AnnualSales.Value) / 1000, 0) & " (#PERCENT{P1})"

The first part divides the sum of AnnualSales by 1,000 and then applies the FormatCurrency function to the result.  The second parameter for FormatCurrency tells the function that we don’t want any decimals.  The result of this function call is concatenated with the second part using Visual Basic string concatenation (&).

The second part looks like a regular string but it contains a built-in keyword: #PERCENT.  This will show the percentage that the slice represents.  Furthermore, there’s a custom string formatter appended: P1.  By default the percentage would show 2 decimals.  This way it will only use one digit for the decimal fraction.

See here for a list of all built-in keywords and this page for more information on the available formatting options.

And following screenshot shows what our chart now looks like.

I’ve also given it a clear title, decreased the Data Label font size to 8 and moved the legend down.

To move the legend: right-click it, select Legend Properties and play with the radio buttons for the Legend Position.

So, we’ve now got a fairly readable chart.  It’s not perfect, some labels are overlapping, but it’s doable.  However, we won’t rest here.  On to the next tip.

Rotating The Pie

Some people may ask you, “Why on earth does the first slice (the blue one representing 10.6% in our example) start at this weird angle at 4 o’clock?  Why can’t it start at 12:00?”.

Again we’re lucky because this can be controlled using a standard property.  Among the Chart Series CustomAttributes property group there are still some properties which haven’t been mentioned earlier.  One of them is called PieStartAngle.  By default it is set to zero.  Funny enough, zero stands for 30°.  Try it out and enter 30 for the property value.  Did you see the effect?  Indeed, nothing happens!  Now enter 90.  Did you see the chart rotate, even in Design mode?  Switch to Preview to get a better view of what the impact is.  As you can see, setting it to 90 will cause the first slice to start at 06:00.  To make it start at 12:00, we thus need to set the property to 270 degrees.

Labels Outside Pie Chart

Other people may tell you, “But I don’t want all these labels on the pie itself, I want them next to it.”.

We’re still lucky because again this can be achieved using standard properties.  Still in the Chart Series CustomAttributes, there’s a property named PieLabelStyle.  Its default value is Inside.  Switching it to Outside will render the labels outside the pie, with lines attaching them to their respective slice.

Other interesting properties for the outside labeling are 3DLabelLineSize and MinimumRelativePieSize.

3DLabelLineSize defines the amount of space used for drawing the line between the label and its corresponding slice and is a percentage of its default size.  Values range from 30 to 200.  I’ve put it to 30 to get as much space as possible for the pie itself and the labels.

MinimumRelativePieSize represents a percentage of the chart area size and defines the minimum acceptable pie size.  Values range from 10 to 70.  I’ve put this one to 70 to maximize the size of the pie.

With these modifications we’ve actually gotten some extra space for the labels.  Let’s take advantage of that and add extra information in the labels.  Change the Data Label expression to the following:

="#LEGENDTEXT" & vbcrlf &
FormatCurrency(Sum(Fields!AnnualSales.Value) / 1000, 0) & " (#PERCENT{P1})"

Our expression uses another built-in keyword: #LEGENDTEXT.  This will add the legend text to the label itself, which means the legend becomes obsolete.  So I’ve removed it.

And this is what our chart now looks like:

With Halloween coming up I thought it would be nice to create a spidery chart

One More Custom Attribute

I’ve already mentioned several CustomAttribute properties of the Chart Series and I’d like to mention one more.  This property is called PieDrawingStyle and it will only appear in the list of properties when 3D is not enabled.  After disabling 3D I could set it to either SoftEdge or Concave.  I also noticed that labels outside of a pie chart will only have lines attached to them when rendered in 3D, so I’ve switched back to Inside for the PieLabelStyle property.

This is what SoftEdge looks like.  I think it’s rather nice.

Custom Coloring

To conclude, there may be some people who tell you, “I don’t like those colours, and I don’t like any of the predefined sets.  I want to specify custom colours.”.

So again we’re lucky because even that is supported by default.

To get started with our color customization, select the chart object.  To know if you’ve made the correct selection, the Property pane should show “Chart” as non-bold part of the dropdown.  Alternatively you can just use that dropdown to select the Chart.  As Chart is a main object on the report, it is shown in the list (whereas parts of a Chart, such as Chart Series and Chart Area, are not shown in that list).

With the Chart selected, locate the Palette property.  By default it is set to BrightPastel.  In case you’re happy with one of the predefined palettes you can just select it here.  But we go for Custom, located at the bottom.

Next, locate the CustomPaletteColors property.  Selecting the property will show a button with an ellipsis as button text.  Click this button to get to the ReportColorExpression Collection Editor (what a name for a popup window!).  This window allows you to specify a list of colors.  I’ve specified the following 10 colors:

And finally this is what our report looks like.  To stay in the theme, I’ve specified some colors which are suitable for Halloween-time charting.

Coloring Consistency Using Dynamic Colors

And now to really conclude this article I’d like to mention one additional tip related to chart coloring.  In some occasions it may be interesting to have coloring consistency between different charting periods.  With that I mean that California would always show in grey, no matter whether it came first or not, Washington as brown, and so on.  This is currently not the case.  With the current implementation it’s the first pie that gets the grey color, the second pie is brown, and so on.

The best way to achieve that is to store the colors in the database and then fetch them in the same dataset that is used to retrieve the chart data.  The AdventureWorks database hasn’t got any color codes stored so I’ll just illustrate what I mean using a little cheat.

In order to get our dynamic coloring working, we will override the colors from the palette.  This is how it’s done.  Right-click on the pie and select Series Properties.  Select the Fill page and click the Expression (fx) button to define the color.  In the case where you’re selecting the color code as one of the database fields, your expression would look similar to this (assuming that colors are stored using their 6-digit hexadecimal representation with 000000 being black and FFFFFF being white):

="#" & Fields!ColourCode.Value

To imitate dynamic coloring I’ve used the following expression:

=Switch
(
    Fields!StateProvinceName.Value = "California", "Blue",
    Fields!StateProvinceName.Value = "Washington", "Red",
    Fields!StateProvinceName.Value = "Florida", "Green",
    True , "#888888"
)

The expression gives three states their own color and all the others will be colored a kind of grey.

This is what it looks like:

So, I hope you’ve enjoyed reading this article.  Feel free to post any comments should you wish to do so, and… happy charting!

References

SQL Server 2008 Books Online: Pie Charts

How to: Collect Small Slices on a Pie Chart

Formatting Data Points on a Chart

How to: Define Colors on a Chart Using a Palette

Two commonly-used functions in Reporting Services are the IIF() and the Switch().  These are two functions of the Program Flow type, or Decision Functions as they are called on this MSDN page.

In case you’re wondering why it’s so difficult to find a function reference for the built-in functions of SSRS, it’s because these are actually Visual Basic functions and Microsoft refers to those for any detailed explanation.  Click this link for the IIF() function in the Visual Basic Language Reference, and this one for the Switch().

Anyone who’s done some programming most likely already knows the if <expression> then <some_code> else <other_code> statement.  If <expression> evaluates to true then <some_code> gets executed, else <other_code>  gets executed.

The IIF() works in the same way.  According to its description it

Returns one of two objects, depending on the evaluation of an expression.

This is its definition:

Public Function IIf( _
ByVal Expression As Boolean, _
ByVal TruePart As Object, _
ByVal FalsePart As Object _
) As Object

Here’s a simple example:

=IIf(Fields!YearlyIncome.Value >= 60000,"High","Low")

Using this expression, the "High" string is returned when the value of the YearlyIncome field is equal to or above 600, while the string "Low" is returned when the value is below 600.

Now have a look at the following example.  It has been nicely structured with indentation and line breaks to make reading easier.

=IIF
(
    Sum(Fields!LineTotal.Value) >= 100,
    "Violet",
    IIF()
    (
        Sum(Fields!LineTotal.Value) < 25,
        "Transparent",
        "Cornsilk"
    )
)

As you see, it shows a nested IIF inside another one.  Imagine that there were several more nestings and that line breaks were not used by the coder.  Would be a nightmare to read, right?

That’s why the Switch() was invented.  The description for the Switch function reads:

Evaluates a list of expressions and returns an Object value corresponding to the first expression in the list that is True.

And this is the function definition:

Public Function Switch( _
    ByVal ParamArray VarExpr() As Object _
) As Object

In Reporting Services, the VarExpr parameter is simply an even list of expressions and/or object references separated by commas.  Which comes down to something like this: Switch(<expr1>, val1, <expr2>, val2).

Here’s a simple example:

=Switch
(
    Fields!State.Value = "OR", "Oregon",
    Fields!State.Value = "WA", "Washington"
)

This expression says that if the value for the State field is "OR" then the Switch function will return "Oregon", and so on…

Now, to get to the point of this article, the Switch function does not contain an ELSE part like the IIF does.

But I wouldn’t be writing this if there wasn’t a workaround, would I?  If you read the Switch’s description closely, it says that it will return the first expression in the list that is true.  So each expression is evaluated in the order that they are passed to the function.  To get ELSE-like behavior we would need an expression that evaluates to True but only when all other expressions are False.  So, why not use True as expression?  It’s the simplest expression that I can think of and it does the works!

Have a look at the following, it’s a rewrite of the last IIF example mentioned earlier.

=Switch
(
    Sum(Fields!LineTotal.Value) >= 100, "Violet",
    Sum(Fields!LineTotal.Value) < 25, "Transparent",
    True, "Cornsilk"
)

So, which one do you think is the most readable?  The IIF, or the Switch?  These are only simple examples that I’ve been using, imagine situations with ten or more possibilities.  Well, I think you’ve got my point by now.

Quick tip for users of Report Builder 2.0: to be able to format your expression with line breaks and tabs, you need to use CTRL + ENTER or CTRL + TAB in the Expression Builder.  Just hitting ENTER will close the popup window.  It’s quite annoying if you’re used to the BIDS interface, but it works

Happy reporting,

Valentino.

This report cannot be run in report builder because it contains one or more embedded data sources with credential options that are not supported.  Instead of embedded data sources use shared data sources or save and view the report on the server.

Okay, no problem I thought, let’s just create a shared data source and switch to that one then.  So I opened up the Data Source Properties in Report Builder and selected the Use a shared connection or report model radio button.

Unfortunately, when running the report it threw me that same error?!  And when I open the Data Source properties again, my change was undone!  It was still using the embedded data source.

As far as I’m concerned that should be a bug.

The only way that I could switch my data source to a shared connection was by creating a new data source, which means you also need to move all datasets connected to the original data source.

Quick tip: if you first rename the original data source and datasets to something like srcMyDataset_OLD, you can give the correct name to the new one straightaway.

So I guess that’s another workaround on my list

This issue was encountered while using Report Builder 2.0 (10.0.2531.0).  I tried to reproduce it using Report Builder 3.0 (10.50.1092.20 – that’s the version of the SQL Server 2008 R2 August CTP) and I couldn’t.  Which means it has been fixed.  Good on you Microsoft!