Question

I have a query here and I’m curious if there is a shorter way of writing this query, meaning to reduce the query from using an IF argument to determine if it should use the param or not in the statement. Please see below:

 @Param varchar(10) = NULL

 IF @Param IS NOT NULL
   BEGIN
     SELECT * FROM TABLE WHERE Column = @Param
   END
 ELSE
   BEGIN
     SELECT * FROM TABLE
   END

Could this be reduced to one simple query instead like this?

 @Param varchar(10) = NULL

 SELECT * FROM TABLE WHERE Column = COALESCE( Any, @Param )

I looked at Coalesce, but didn’t see if I could use an Any sort of feature. I hope this makes sense.

Question is how to acheive this. Second question is which would be better on performance?

Answer 1

There is no any style command, but if you use the @Param first and then the value in the column itself, that should work…

SELECT * FROM TABLE WHERE Column = COALESCE(@Param, Column)

If @Param is Null then it is ignored and the next item in the list is used.

You can also use IsNull to do the same thing…

SELECT * FROM TABLE WHERE Column = ISNULL(@Param, Column)

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To answer the 2nd part of the question, my feeling is that using a separate statement will always be more efficient. The condensed version might be less code, but isn’t necessarily easier to understand or quicker to run.