mysql判断语句 if

DELIMITER //

CREATE PROCEDURE UpdatePosition()
BEGIN
    DECLARE emp_id INT;
    DECLARE emp_salary DECIMAL(10, 2);
    DECLARE emp_position VARCHAR(50);

    -- 假设我们有一个游标来遍历员工表
    DECLARE cur CURSOR FOR SELECT id, salary FROM employees;
    OPEN cur;

    read_loop: LOOP
        FETCH cur INTO emp_id, emp_salary;
        IF emp_salary > 5000 THEN
            SET emp_position = '高级工程师';
        ELSEIF emp_salary > 3000 THEN
            SET emp_position = '中级工程师';
        ELSE
            SET emp_position = '初级工程师';
        END IF;

        -- 更新员工职位
        UPDATE employees SET position = emp_position WHERE id = emp_id;
    END LOOP;

    CLOSE cur;
END //

DELIMITER ;

IF emp_salary > 5000 THEN
    SELECT 'High Salary' AS Position;
ELSEIF emp_salary > 3000 THEN
    SELECT 'Medium Salary' AS Position;
ELSE
    SELECT 'Low Salary' AS Position;
END IF;