将SSRS参数转换为Null

Question

I have SSRS report that showing Marketing Features. we have in the MF a field called "Test", the values are "PSI 1" or PSI 2" and also the field can be empty.

I added a dataset for the Test parameter with this query:

SELECT DISTINCT Corp_Test
  FROM [Tfs_Warehouse].[dbo].[CurrentWorkItemView]
 WHERE ProjectNodeGUID = @ProjectGuid
   AND System_WorkItemType = 'Marketing Feature'
UNION
SELECT 'Null'
ORDER BY Corp_Test

Now in the report, the values are PSI 1 PSI 2 and Null :

In the Main Query I filtered the results according to the parameter like this:

where COALESCE(Corp_Test, 'Null') IN (@TestParam)

The report works fine, and if I selected all values I get also Marketing Features with empty Test field.

My question is:

Instead of Null on the dropdown, I want it to be written No PSI and actually in the main query it will be Null. is it possible?

Answer 1

In your parameter properties, on the Available Values screen you will see an option for the Value and the Label . This allows you to show one thing to the end user (eg: user friendly description) whilst passing another (eg: key value) to the report.

In your dataset for the test parameter add a column to hold the Label of the value you want to pass through to the query. This can be the same as your Value if you so wish, but gives you the flexibility you require on the Null entry:

SELECT DISTINCT Corp_Test as Value
               ,Corp_Test as Label
  FROM [Tfs_Warehouse].[dbo].[CurrentWorkItemView]
 WHERE ProjectNodeGUID = @ProjectGuid
   AND System_WorkItemType = 'Marketing Feature'
UNION ALL           -- As you have DISTINCT above, UNION ALL will work faster and give the same results as UNION (which removes duplicates)
SELECT 'Null' as Value
      ,'No PSI' as Label
ORDER BY Corp_Test

Once you have done this, change your parameter to use the Value field as the parameter value and the Label field as the label shown to the user.

Answer 2

SELECT
ISNULL(Corp_Test,'No PSI') AS Corp_Test
FROM 
(SELECT DISTINCT Corp_Test
  FROM [Tfs_Warehouse].[dbo].[CurrentWorkItemView]
 WHERE ProjectNodeGUID = @ProjectGuid
   AND System_WorkItemType = 'Marketing Feature'
UNION
SELECT 'Null'
) AS Corp
ORDER BY ISNULL(Corp_Test,'No PSI') 

Remember to implement the change in your where clause main query. By main query, I mean the query that is feeding your report

Answer 3

The simple and easiest way is what @sgeddes answered in his comment.

I just repleced the where COALESCE(Corp_Test, 'Null') IN (@TestParam) with where COALESCE(Corp_Test, 'No PSI') IN (@TestParam) , and in the dataset I replaced the SELECT 'Null' with SELECT 'No PSI' .