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Do we have is null check in POSTGRESQL 8.4? In MS SQL 2005 we have check like ISNULL(@myPassedValue, "MyDefaultValue")

shenoyroopesh
on
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Last Modified: 2012-05-08
Hi..
     Recently i have started working in Postgresql 8.4. Im trying to write select and update queries inside a function. I will be passing different parameters to the function. Here is the code example

Select * from TABLE1
where COLUMN1 = isnull(@passedValue1, COLUMN1)
    and COLUMN2 = isnull(@passedValue1, COLUMN2)
/*select query wil consider the passed parameter only if it is not null.*/

above query works fine with MSSQL SERVER 2005. But it throws the syntax error when i execute it in POSTGRESQL 8.4.

Can anyone help me in finding the syntax for using ISNULL
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Commented:
You can simply write:

Select * from TABLE1
where @passedValue1 IS NULL OR (COLUMN1 = @passedValue1 AND COLUMN2 = @passedValue1)

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Commented:
Hey thanks it worked.. I used
     SELECT * FROM "TABLE1"      
     WHERE (@passedValue1 IS NULL OR ("COL1" = @passedValue1))
       AND (@passedValue2 IS NULL OR ("COL2" = @passedValue1));  

but my problem with update is still there,

UPDATE TABLE1
      set COLUMN1 = ISNULL(@passedValue1 , COLUMN1),
              COLUMN2 = ISNULL(@passedValue2 , COLUMN2),

I will be updating only those columns for which values are passed else old values are retained.

can u suggest the solution for this..
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Commented:
you could  build the update statement dynamically for each column that you want to change.
Otherwise I can't conceive a method of doing the update.
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Commented:
More info about available POSTGRE functions is e.g. here: http://www.postgresql.org/files/documentation/pdf/8.4/postgresql-8.4.1-A4.pdf

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