Inline Table Functions with IF or Case Statement

  • hi Guys -

    I am trying to create one function with multiple sub queries based on the param value passed in. If i try to use the IF statement I get a scalar variable Declare issue, If I use the case select it seems to fail on my second WHEN statement?

    Any ideas on how to effectively do this?

    ALTER FUNCTION [dbo].[myFunction](

    @Usage_Date SmallDAteTime,

    @RateCode Varchar(4)

    )

    RETURNS TABLE AS

    RETURN

    SELECT CASE

    WHEN (@RateCode = 'O07') THEN

    (

    select Rate=case

  • fergfamster (5/26/2016)


    hi Guys -

    I am trying to create one function with multiple sub queries based on the param value passed in. If i try to use the IF statement I get a scalar variable Declare issue, If I use the case select it seems to fail on my second WHEN statement?

    Any ideas on how to effectively do this?

    ALTER FUNCTION [dbo].[myFunction](

    @Usage_Date SmallDAteTime,

    @RateCode Varchar(4)

    )

    RETURNS TABLE AS

    RETURN

    SELECT CASE

    WHEN (@RateCode = 'O07') THEN

    (

    select Rate=case

    CASE is an expression. It is used to control the return value of a single column. It is NOT used to control flow. Perhaps if you can provide us some more details we can help you figure out how to do whatever it is you are trying to do. At the very least some kind of explanation would help. DDL and sample data would be a big plus but not totally sure it is needed here.

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  • If the table structures to be returned are the same for all conditions, you can use UNION ALL with the appropriate WHERE conditions so that only one query ever returns results:

    ...

    RETURN (

    SELECT ...

    FROM ...

    WHERE @RateCode = '007'

    UNIO N AL L

    SELECT ...

    FROM ...

    WHERE @RateCode = '008'

    UNIO N AL L

    SELECT ...

    FROM ...

    WHERE @RateCode = '009'

    ...

    )

    SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".

  • ScottPletcher (5/26/2016)


    If the table structures to be returned are the same for all conditions, you can use UNION ALL with the appropriate WHERE conditions so that only one query ever returns results:

    ...

    RETURN (

    SELECT ...

    FROM ...

    WHERE @RateCode = '007'

    UNIO N AL L

    SELECT ...

    FROM ...

    WHERE @RateCode = '008'

    UNIO N AL L

    SELECT ...

    FROM ...

    WHERE @RateCode = '009'

    ...

    )

    Does this mean all queries are from different tables?

  • djj (5/26/2016)


    ScottPletcher (5/26/2016)


    If the table structures to be returned are the same for all conditions, you can use UNION ALL with the appropriate WHERE conditions so that only one query ever returns results:

    ...

    RETURN (

    SELECT ...

    FROM ...

    WHERE @RateCode = '007'

    UNIO N AL L

    SELECT ...

    FROM ...

    WHERE @RateCode = '008'

    UNIO N AL L

    SELECT ...

    FROM ...

    WHERE @RateCode = '009'

    ...

    )

    Does this mean all queries are from different tables?

    Yes, they definitely can be. As long as the result sets are all compatible, the queries can be from different tables, have different joins, etc..

    SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".

  • Each expression used is for a reason to call a different query under each. "If statements" require declaring a variable and that errors, so was trying to find a work around. The variable would fail on declaring a Table Scalar Value after the Returns statement

    IE:

    IF @RateCode = ''

    Query

    ELSE IF

    Query

    Else

  • Sorry Scott, I thought the OP had left some code. :hehe:

    I really need to read more carefully

  • fergfamster (5/26/2016)


    Each expression used is for a reason to call a different query under each. "If statements" require declaring a variable and that errors, so was trying to find a work around. The variable would fail on declaring a Table Scalar Value after the Returns statement

    IE:

    IF @RateCode = ''

    Query

    ELSE IF

    Query

    Else

    Without you showing us what you are trying to accomplish there is very little chance that any shots in the dark are going to help you.

  • Well I gave the code at the beginning.

    here is my original with 1 inline query:

    SET ANSI_NULLS ON

    GO

    SET QUOTED_IDENTIFIER ON

    GO

    ALTER FUNCTION [dbo].[MyFunction](

    @Usage_Date SmallDAteTime,

    @RateCode Varchar(4)

    )

    RETURNS TABLE AS

    RETURN

    select, where

    group By ....

    My New Query Im simply trying to use an IF statement to have 4 different types of queries based on the variable value for rateCode. When trying to use an If statement I get an error like the one below stating Declare Table Scalar Variable. Its declared directly after the function name for the variables passed, however seems to not like being used with if statements or case statements other than just calling the variable name itself in my query directly.

    SET ANSI_NULLS ON

    GO

    SET QUOTED_IDENTIFIER ON

    GO

    ALTER FUNCTION [dbo].[MyFunction](

    @Usage_Date SmallDAteTime,

    @RateCode Varchar(4)

    )

    RETURNS TABLE AS

    RETURN

    IF @RateCode = 'O07'

    (

    select Rate=case

    Group By ...

    )

    ELSE IF @RateCode = 'O01'

    (

    select Rate=case

    Group By ...

    )

  • fergfamster (5/26/2016)


    Well I gave the code at the beginning.

    here is my original with 1 inline query:

    SET ANSI_NULLS ON

    GO

    SET QUOTED_IDENTIFIER ON

    GO

    ALTER FUNCTION [dbo].[MyFunction](

    @Usage_Date SmallDAteTime,

    @RateCode Varchar(4)

    )

    RETURNS TABLE AS

    RETURN

    select, where

    group By ....

    My New Query Im simply trying to use an IF statement to have 4 different types of queries based on the variable value for rateCode. When trying to use an If statement I get an error like the one below stating Declare Table Scalar Variable. Its declared directly after the function name for the variables passed, however seems to not like being used with if statements or case statements other than just calling the variable name itself in my query directly.

    SET ANSI_NULLS ON

    GO

    SET QUOTED_IDENTIFIER ON

    GO

    ALTER FUNCTION [dbo].[MyFunction](

    @Usage_Date SmallDAteTime,

    @RateCode Varchar(4)

    )

    RETURNS TABLE AS

    RETURN

    IF @RateCode = 'O07'

    (

    select Rate=case

    Group By ...

    )

    ELSE IF @RateCode = 'O01'

    (

    select Rate=case

    Group By ...

    )

    Everything you have given so far is incomplete. No idea what you have and are trying to accomplish by giving us snippets of your code. Sorry.

  • Ok, well i cant give you all my code. If you wanted to create an Inline function and have separate queries returned based on an IF statement is the bottom line or a case statement etc.. these are not union all type queries. Its ok, ill figure it out.

  • fergfamster (5/26/2016)


    Ok, well i cant give you all my code. If you wanted to create an Inline function and have separate queries returned based on an IF statement is the bottom line or a case statement etc.. these are not union all type queries. Its ok, ill figure it out.

    Then create something unique that mirrors your current problem, just be sure it mirrors it completely and you don't leave out something important.

  • fergfamster (5/26/2016)


    Ok, well i cant give you all my code. If you wanted to create an Inline function and have separate queries returned based on an IF statement is the bottom line or a case statement etc.. these are not union all type queries. Its ok, ill figure it out.

    As I said originally....case is an expression. It is NOT used to control flow like an IF statement. You have to keep in mind that we can't see your screen, we have no idea what your tables are like, we have no idea what your project is. The only details we have are what you have posted and at this point all you have posted is portions of a query and an incredibly vague description of what you want it to do. There are least 4 different people in here trying to help you but for that to succeed you have to help us by providing the details of your problem. Without those details we are shooting blindly. It does not have to be your actual query or even anything revealing the true nature of the problem. But it does have to have the same level of detail.

    _______________________________________________________________

    Need help? Help us help you.

    Read the article at http://www.sqlservercentral.com/articles/Best+Practices/61537/ for best practices on asking questions.

    Need to split a string? Try Jeff Modens splitter http://www.sqlservercentral.com/articles/Tally+Table/72993/.

    Cross Tabs and Pivots, Part 1 – Converting Rows to Columns - http://www.sqlservercentral.com/articles/T-SQL/63681/
    Cross Tabs and Pivots, Part 2 - Dynamic Cross Tabs - http://www.sqlservercentral.com/articles/Crosstab/65048/
    Understanding and Using APPLY (Part 1) - http://www.sqlservercentral.com/articles/APPLY/69953/
    Understanding and Using APPLY (Part 2) - http://www.sqlservercentral.com/articles/APPLY/69954/

  • fergfamster (5/26/2016)


    Ok, well i cant give you all my code. If you wanted to create an Inline function and have separate queries returned based on an IF statement is the bottom line or a case statement etc.. these are not union all type queries. Its ok, ill figure it out.

    You don't have to give all your code. Not even real column or table names. But we would expect you to at least post an accurate mock up and use FROM in your SELECT statements, as well as number of columns.

    I saw this before anyone answered, but you didn't provide anything that allows us to give you an adequate solution.

    Luis C.
    General Disclaimer:
    Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?

    How to post data/code on a forum to get the best help: Option 1 / Option 2
  • From what you describe, this sounds like a very poor usage of an inline function.

    Is this what you are doing:

    SELECT

    field,

    field,

    inline_function

    FROM Table

    My suggestion is to re-think this.

    Michael L John
    If you assassinate a DBA, would you pull a trigger?
    To properly post on a forum:
    http://www.sqlservercentral.com/articles/61537/

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