mysql if语句用法

IF condition THEN
    -- 当条件为真时执行的语句块
ELSE
    -- 当条件为假时执行的语句块（可选）
END IF;

DELIMITER //

CREATE PROCEDURE UpdatePositionLevel()
BEGIN
    DECLARE emp_salary DECIMAL(10, 2);
    DECLARE emp_position VARCHAR(50);
    
    -- 假设我们有一个游标来遍历employees表中的每一行
    OPEN cur_employee;
    
    read_loop: LOOP
        FETCH cur_employee INTO emp_salary, emp_position;
        
        IF emp_salary > 10000 THEN
            UPDATE employees SET position_level = '高级' WHERE CURRENT OF cur_employee;
        ELSEIF emp_salary > 5000 THEN
            UPDATE employees SET position_level = '中级' WHERE CURRENT OF cur_employee;
        ELSE
            UPDATE employees SET position_level = '初级' WHERE CURRENT OF cur_employee;
        END IF;
        
        IF NOT FOUND THEN
            LEAVE read_loop;
        END IF;
    END LOOP;
    
    CLOSE cur_employee;
END //

DELIMITER ;