SQL Switch/Case in 'where' clause

without a case statement...

SELECT column1, column2
FROM viewWhatever
WHERE
    (@locationType = 'location' AND account_location = @locationID)
    OR
    (@locationType = 'area' AND xxx_location_area = @locationID)
    OR
    (@locationType = 'division' AND xxx_location_division = @locationID)

The problem with this is that when the SQL engine goes to evaluate the expression, it checks the FROM portion to pull the proper tables, and then the WHERE portion to provide some base criteria, so it cannot properly evaluate a dynamic condition on which column to check against.

You can use a WHERE clause when you're checking the WHERE criteria in the predicate, such as

WHERE account_location = CASE @locationType
                              WHEN 'business' THEN 45
                              WHEN 'area' THEN 52
                         END

so in your particular case, you're going to need put the query into a stored procedure or create three separate queries.


Here you go.

SELECT
   column1, 
   column2
FROM
   viewWhatever
WHERE
CASE 
    WHEN @locationType = 'location' AND account_location = @locationID THEN 1
    WHEN @locationType = 'area' AND xxx_location_area = @locationID THEN 1
    WHEN @locationType = 'division' AND xxx_location_division = @locationID THEN 1
    ELSE 0
END = 1

declare @locationType varchar(50);
declare @locationID int;

SELECT column1, column2
FROM viewWhatever
WHERE
@locationID = 
  CASE @locationType
      WHEN 'location' THEN account_location
      WHEN 'area' THEN xxx_location_area 
      WHEN 'division' THEN xxx_location_division 
  END