SQL Server - Execute first where clause and if valid don't execute second

Question

I have the SQL Server Select statement:

SELECT * 
FROM Table
WHERE(ClientPlants = 621 AND Carriers = 226)
 OR (Carriers = 226 AND ClientPlants IS NULL) 
 ORDER BY ClientPlants

Now problem is when the first is valid, it still executes the second clause after the 'or'. How do I make it so the second clause is only executed if the first clause fails?

As in, if there are no results found for where clause 1 (ClientPlants = 621 AND Carriers = 226), go to 2 (Carriers = 226 AND ClientPlants IS NULL). If there is a result for clause 1, return query and stop.

I tried to look into CASE statement but couldn't see how to add it to my code.

Thanks in advance!

Answer 1

Do you mean something like this:

IF EXISTS (SELECT * FROM Table WHERE ClientPlants = 621 AND Carriers = 226)
    SELECT * FROM Table WHERE ClientPlants = 621 AND Carriers = 226 ORDER BY ClientPlantsK
ELSE
    SELECT * FROM Table WHERE Carriers = 226 ORDER BY ClientPlantsK
;

Update:

Given that you are only wanting to return 1 row, I think something like this would work for a single T-SQL query in a stored procedure:

CREATE PROCEDURE ProcedureName
    @ClientPlants int
    , @Carriers int
AS

SELECT
    Carriers
    , ClientPlants
    -- Add the rest of the columns
FROM
    (
        SELECT
            Carriers
            , ClientPlants
            -- Add the rest of the columns
            , ROW_NUMBER() OVER (ORDER BY CASE WHEN ClientPlants = @ClientPlants THEN 0 ELSE 1 END) R
        FROM Table
        WHERE Carriers = @Carriers
    ) Q
WHERE R = 1

Usage:

EXEC ProcedureName 621, 226

I've recommended you name your columns rather than using SELECT * to avoid having column R in the output.