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sql-server-2012-express

Recursive SQL function, <= operator doesn't work

I just wonder why this works. But what I have comment doesn't work.

ALTER PROC spFactorial
    @ValueIn int,
    @ValueOut int OUTPUT
AS
    DECLARE @InWorking int;
    DECLARE @OutWorking int;

    IF @ValueIn <> 1            -- this <= doesn't work??
    BEGIN
         SELECT @InWorking = @ValueIn - 1;

         EXEC spFactorial @InWorking, @OutWorking OUTPUT;

         SELECT @ValueOut = @ValueIn * @OutWorking;
    END
    ELSE
    BEGIN
        SELECT @ValueOut = 1;
    END

    RETURN;
GO

DECLARE @WorkingOut int;
DECLARE @WorkingIn int;
SELECT @WorkingIn = 3;

EXEC spFactorial @WorkingIn, @WorkingOut OUTPUT;

PRINT CAST(@WorkingIn AS varchar ) + ' factorial is '
+ CAST(@WorkingOut AS VARCHAR );

This IF @ValueIn <= 1 doesn't work - why?

In C# or java it works.

Thank you

Solution 
  • <= is not an operator in SQL. In c# and Java it is.

    For <= operator functionality in Sql, you can do this

    IF(@value < 1 OR @value = 1)