Stored Procedure T-SQL If boolean check

The corresponding sql data type to boolean is bit, meaning 1 for true and 0 for false, so:

IF( @Statement=1)
    BEGIN
        SELECT COUNT(*) FROM Table
    END
ELSE
    BEGIN
        SELECT MIN(ID) FROM Table
    END
END

DECLARE @bool BIT = 1

IF @bool = 1
BEGIN
    -- do stuff here
    PRINT 'it was true';
END
ELSE
BEGIN
    -- do other stuff here
    PRINT 'it was not true';
END

If you've only got a single line inside the if then you don't need the BEGIN and END, but it's probably good practice to use them anyway.

Starting with SQL Server 2012 IIF is shorthand way of writing IF THEN ELSE for assignment:

    DECLARE @str VARCHAR(10);
    SET @str = IIF(1=1, 'Yes', 'No');