Ignoring a NULL parameter in T-SQL

Question

I want to be able to pass in a list of parameters, and ignore the ones which are NULL. So that the query is in effect pretending that the filter isn\'t there and ignoring it

Answer 1

Thanks, This was helpful. I have decided to use the sp_ExecuteSQL method due to the potential performance advantages mentioned. I have a slightly different take on it which you may find helpful.

DECLARE @sql nvarchar(4000) 
DECLARE @where nvarchar(1000) =''

SET @sql = 'SELECT * FROM MyTable'

IF @Param1 IS NOT NULL 
    SET @where = @where + ' AND Field1 = @Param1'

IF @Param2 IS NOT NULL 
    SET @where = @where + ' AND Field2 = @Param2' 

IF @Param3 IS NOT NULL 
    SET @where = @where + ' AND Field3 = @Param3' 

-- Add WHERE if where clause exists, 1=1 is included because @where begins with AND
IF @where <> ''
    SET @sql = @sql + ' WHERE 1=1' + @where

--Note that we could also create order parameters and append here
SET @sql = @sql + ' ORDER BY Field1'