SQL Query Combine with string

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SQL Query Combine with string

MoreanK

Mr or Mrs. 500

Points: 540
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March 5, 2005 at 3:29 am

#60239

Hello!
        I would like to know one thing : how to combine condition string with query statement.
eg.
IF @Value = 0
     Set @STR = 'AND ID = 100'
ELSE
      Set @STR = 'AND ID = 200'
SELECT ID,Name,Description
FROM Table1
WHERE Name = 'AA' & @STR
I want to use something like that? Please help me....

Viewing 7 posts - 1 through 6 (of 6 total)

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sellertools Old Hand Points: 365 More actions · Answer 1

Something like this should cut it for you:

Declare @sql as varchar(200)

Declare @Value int

Set @sql = 'SELECT ID, Name, Description FROM Table1 WHERE Name = ''A'''

IF @Value = 0

BEGIN

Set @sql = @sql + ' AND ID = 100'

END

ELSE

BEGIN

Set @sql = @sql + ' AND ID = 200'

END

execute(@SQL)

Jeff Moden SSC Guru Points: 1004362 More actions · Answer 2

Actually, it can be done without the overhead of Dynamic SQL by using a CASE statement in the WHERE clause....

SELECT ID,Name,Description FROM Table1 WHERE Name = 'AA' AND ID = CASE WHEN @Value = 0 THEN 100 ELSE 200 END

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

MoreanK Mr or Mrs. 500 Points: 540 More actions · Answer 3

Dear Grasshopper,

Thanks for your answer but my query statement is long, over 255 characters. So I have to seperate many strings, isn't it?

Best Regards,

MK.

Jeff Moden SSC Guru Points: 1004362 More actions · Answer 4

Morean,

SellerTools' answer can easily be modified to handle 8000 characters just by changing "Declare @sql as varchar(200)" to "Declare @sql as varchar(8000)". Still, it's dynamic SQL and might be better off adding the CASE statement to the WHERE clause... and then you don't have to worry about such things, either.

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

sellertools Old Hand Points: 365 More actions · Answer 5

hey grasshopper,

I agree with Jeff that more than likely, you are better off making a smarter statement rather than resorting to dynamic SQL. I think the only time I personally have had to use dynamic SQL was in the creation of tables. I tdoes have its places, but with the example that you gave, either a CASE statement would work, or even better would be something like;

Create Procedure dbo.MyProcedure

(

@Value as int

)

Declare @IDValue as int

if @Value=0

BEGIN

Set @IDValue = 100

End

Else

BEGIN

SET @IDValue = 200

END

BEGIN

SELECT

ID,

Name,

Description

FROM Table1 WHERE Name = 'AA' AND ID = @IDValue

END

GO

MoreanK Mr or Mrs. 500 Points: 540 More actions · Answer 6

MoreanK

Mr or Mrs. 500

Points: 540

March 8, 2005 at 1:29 am

#545821

Grasshopper,

Thanks a lot!

MK.