mysql数据库 循环语句怎么写

DELIMITER //

CREATE PROCEDURE example_while_loop()
BEGIN
    DECLARE counter INT DEFAULT 0;

    WHILE counter < 5 DO
        SELECT counter;
        SET counter = counter + 1;
    END WHILE;
END //

DELIMITER ;

CALL example_while_loop();

DELIMITER //

CREATE PROCEDURE example_repeat_loop()
BEGIN
    DECLARE counter INT DEFAULT 0;

    REPEAT
        SELECT counter;
        SET counter = counter + 1;
    UNTIL counter >= 5 END REPEAT;
END //

DELIMITER ;

CALL example_repeat_loop();

DELIMITER //

CREATE PROCEDURE example_loop()
BEGIN
    DECLARE counter INT DEFAULT 0;

    loop_label: LOOP
        SELECT counter;
        SET counter = counter + 1;

        IF counter >= 5 THEN
            LEAVE loop_label;
        END IF;
    END LOOP;
END //

DELIMITER ;

CALL example_loop();

DELIMITER //

CREATE PROCEDURE example_transaction_loop()
BEGIN
    DECLARE counter INT DEFAULT 0;
    DECLARE EXIT HANDLER FOR SQLEXCEPTION
    BEGIN
        ROLLBACK;
        RESIGNAL;
    END;

    START TRANSACTION;

    WHILE counter < 5 DO
        -- 执行数据库操作
        INSERT INTO table_name (column_name) VALUES (counter);
        SET counter = counter + 1;
    END WHILE;

    COMMIT;
END //

DELIMITER ;

CALL example_transaction_loop();