SQL Where Cluase - Use Parameter if passed

CREATE PROC [dbo].[mySPROC]
             @ID as INT = null

AS
BEGIN
    IF @ID is not null
      SELECT *
        FROM MyTable
        WHERE ID = @ID
    ELSE
      SELECT *
        FROM MyTable
END

was hoping there was another solution as my SELECT statement is quite long

Then you'll need to resort to dynamic SQL but your best bet is to have an if statement in there and do one or the other.

Either of the above will work, alough I typically use DanielWilson's method.

Also, if you have multiple WHERE expressions, make sure you use parenthesis so that it evaluates together, such as..

WHERE customer_id = 1
      AND hell_freezes_over = True
     AND (ID = @id OR @ID IS NULL)

@DanielWilson your solution does work.  

I should have added more info but didnt' think I needed to.  Here is the problem I am having with the solution.

CREATE PROC [dbo].[mySPROC]
             @ID as INT = null,
             @dtStart as DATETIME = null,
             @dtEnd as DATETIME = null

AS
BEGIN
      SELECT *
        FROM MyTable
        WHERE (ID = @ID OR @ID is NULL)
        AND ((MyDate >= @dtStart And MyDate <= @dtEnd) 
                   OR (@dtStart IS NULL And @DtEnd IS NULL))
END 

Select all Open in new window

EXEC mySPROC - DOES NOT WORK
EXEC mySPROC '11/1/12', 11/30/12', NULL - DOES NOT WORK
EXEC mySPROC NULL, NULL, 31 - WORKS

Any ideas?

It works - was a typo on my end.  Thx

Works like a charm!