mysql 存储过程遍历

CREATE TABLE employees (
    id INT PRIMARY KEY,
    name VARCHAR(100),
    department VARCHAR(50)
);

DELIMITER //

CREATE PROCEDURE TraverseEmployees()
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE emp_id INT;
    DECLARE emp_name VARCHAR(100);
    DECLARE emp_department VARCHAR(50);

    -- 定义游标
    DECLARE cur CURSOR FOR SELECT id, name, department FROM employees;
    -- 定义结束标志
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN cur;

    read_loop: LOOP
        FETCH cur INTO emp_id, emp_name, emp_department;
        IF done THEN
            LEAVE read_loop;
        END IF;

        -- 在这里处理每一行数据
        SELECT emp_id, emp_name, emp_department;
    END LOOP;

    CLOSE cur;
END //

DELIMITER ;

CALL TraverseEmployees();