Know Your MYSQL: IF and ELSE

We can IF and ELSE control structure in two ways in MYSQL. If you are creating a procedure and you want to use IF and ELSE control structure in your stored procedure. IF syntax : IF search_condition THEN statement_list [ELSEIF search_condition THEN statement_list] … [ELSE statement_list] END IF For example : MYSQL > BEGIN > IF (userId <> ”) && (userId <> 0) then > SELECT * FROM user_table where user_id = userId; > END IF; > END In this case this procedure will run the select statement only if userId is not equal to ” and 0 Next example : MYSQL > BEGIN > IF (userType = “emp”) then > select * from emp_table where user_id = userId; > ELSE IF (userType = “Admin”) > select * from admin_table where user_id = userId; > ELSE > select * from user_table where user_id = userId; > END IF; > END In this case we are first checking the the type of userType by comparing it with d...