Question

I need to write result of EXISTS function to a variable. I read that SQL Server has no ‘bool’ variables, so I want to store the result in a bit variable. And vice versa convert from ‘bit’ to ‘bool’. How can I achieve it?

Answer 1

DECLARE @bool BIT;

SELECT @bool = CASE WHEN EXISTS (some subquery) THEN 1 ELSE 0 END;

I don’t know what vice versa means. SQL Server doesn’t have a boolean data type, so I don’t know what you want to convert a BIT to… maybe:

SELECT CASE WHEN @bool = 1 THEN 'True' ELSE 'False' END;

If you’re trying to do this in an IF statement:

IF @bool = 1
BEGIN
  PRINT 'True';
END
ELSE
BEGIN
  PRINT 'False';
END

If you’re looking for shorthand, where you can say IF (@bool) instead of IF (@bool) = 1, sorry, but you’re out of luck. If this is where you are trying to “optimize” your code and you don’t have more pressing problems, go home for the day and have a beer, you’ve earned it. Saving two characters has already cost you more time than it will ever gain you.