mysql循环查询例子

DELIMITER //

CREATE PROCEDURE process_data()
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE v_id INT;
    DECLARE v_name VARCHAR(255);
    DECLARE cur CURSOR FOR SELECT id, name FROM your_table;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN cur;

    read_loop: LOOP
        FETCH cur INTO v_id, v_name;
        IF done THEN
            LEAVE read_loop;
        END IF;

        -- 在这里执行你需要的操作，比如更新或计算
        -- UPDATE your_table SET some_column = some_value WHERE id = v_id;

    END LOOP;

    CLOSE cur;
END //

DELIMITER ;

CALL process_data();