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handling null paramters in query

  • October 18, 2010 at 2:05 pm

    #225112

    Hi,

    I have written one parameterized query which looks like below -

    select *

    from table

    where Column1 = Case when @parameter1 is NULL then Column1 else @parameter1 end

    and Column2 = Case when @parameter2 is NULL then Column2 else @parameter2 end

    In the above query, I have done validation for NULL value in parameter, means When there comes Value in the parameter then only use it else take all column values...

    Now when I use this, it takes so long like around 30-40 minutes for query to execute and if I remove this null checking option and use heardcoded values for testing then query executes in just 10-20 seconds... !

    Any other way to handle NULL parameters??? :crazy:

    :rolleyes:

  • October 18, 2010 at 3:11 pm

    #1238749

    Sacheen (10/18/2010)

    Hi,

    I have written one parameterized query which looks like below -

    select *

    from table

    where Column1 = Case when @parameter1 is NULL then Column1 else @parameter1 end

    and Column2 = Case when @parameter2 is NULL then Column2 else @parameter2 end

    I think the problem in your where clause. You are saying if @parameter is not null to get all rows.

    if @parameter1 is null you code would the same as..

    select * from table where Column1 = Column1

    Or maybe this a way to work around a dynamic number of parameters being passed in?

    That being said are there any indexes on these columns? Are there lots of rows in the table, etc etc etc.

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  • October 18, 2010 at 3:13 pm

    #1238752

    http://sqlinthewild.co.za/index.php/2009/03/19/catch-all-queries/

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

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