我正在构建一个执行 10-12 个 SQL 语句的存储过程。我收到错误 1172,结果由多行组成
。我正在尝试找出哪个语句负责。
最明显的方法是返回引发错误的语句的 SQL。
这是我的退出处理程序:
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
GET DIAGNOSTICS @n = NUMBER, @c = ROW_COUNT;
GET DIAGNOSTICS CONDITION @n
@s = RETURNED_SQLSTATE,
@m = MESSAGE_TEXT,
@e = MYSQL_ERRNO;
ROLLBACK;
SELECT @s as RETURNED_SQLSTATE, @e as MYSQL_ERRNO, @m as MESSAGE_TEXT, @n as NUMBER, @c as ROW_COUNT;
END;
我可以添加什么,以便它告诉我哪个 SQL 语句生成了错误?
作为引用,这里是完整的存储过程:
DROP PROCEDURE IF EXISTS `unlink_item`;
CREATE PROCEDURE `unlink_item` (
IN item_id varchar(36),
IN parent_id varchar(36),
IN author varchar(64),
IN conversation_id varchar(36),
IN transaction_id varchar(36)
)
BEGIN
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
GET DIAGNOSTICS @n = NUMBER, @c = ROW_COUNT;
GET DIAGNOSTICS CONDITION @n
@s = RETURNED_SQLSTATE,
@m = MESSAGE_TEXT,
@e = MYSQL_ERRNO;
ROLLBACK;
SELECT @s as RETURNED_SQLSTATE, @e as MYSQL_ERRNO, @m as MESSAGE_TEXT, @n as NUMBER, @c as ROW_COUNT;
END;
START TRANSACTION;
SET @when = now();
-- identify the record we are supposed to delete --
SET @deleted = '123';
SELECT `id`
FROM `item_contains`
WHERE `parent_id` = parent_id
AND `child_id` = item_id
INTO @deleted;
-- delete the record --
DELETE FROM `item_contains`
WHERE `id` = @deleted;
-- update the change history for the item_contains table --
INSERT INTO `change_history` (
`date_time`,
`author`,
`action`,
`table_name`,
`record_id`,
`conversation_id`,
`transaction_id`
) VALUES (
@when,
author,
'delete',
'item_contains',
@deleted,
conversation_id,
transaction_id
);
-- update the change history for the parent item --
INSERT INTO `change_history` (
`date_time`,
`author`,
`action`,
`table_name`,
`record_id`,
`conversation_id`,
`transaction_id`
) VALUES (
@when,
author,
concat('unlink from ',parent_id),
'item',
item_id,
conversation_id,
transaction_id
);
-- update the change history for the item being unlinked --
INSERT INTO `change_history` (
`date_time`,
`author`,
`action`,
`table_name`,
`record_id`,
`conversation_id`,
`transaction_id`
) VALUES (
@when,
author,
concat('unlink ',item_id, ' from this'),
'item',
parent_id,
conversation_id,
transaction_id
);
-- if the unlinked item is now orphaned either delete it if it is empty, or re-attach it somewhere to make it accessible --
SET @instances = 0;
SELECT count(`id`)
FROM `item_contains`
WHERE `child_id` = item_id
INTO @instances;
IF ( @instances = 0 ) THEN
SET @children = 0;
SELECT count(`id`)
FROM `item_contains`
WHERE `parent_id` = item_id
INTO @children;
IF ( @children = 0 ) THEN
-- delete the now inaccessible item from the database --
DELETE FROM `item`
WHERE `id` = item_id;
-- update the change history for that item --
INSERT INTO `change_history` (
`date_time`,
`author`,
`action`,
`table_name`,
`record_id`,
`conversation_id`,
`transaction_id`
) VALUES (
@when,
author,
'delete',
'item',
item_id,
conversation_id,
transaction_id
);
ELSE
-- get the ID of the orphan folder --
SET @orphan_id = '123';
SELECT `id`
FROM `item`
WHERE `name` = '### orphans ###'
INTO @orphan_id;
-- move the item into the orphan folder --
SET @inserted = uuid();
INSERT INTO `item_contains` (
`id`,
`parent_id`,
`child_id`
) VALUES (
@inserted,
@orphan_id,
item_id
);
-- update the change history to reflect the orphaning of the item --
INSERT INTO `change_history` (
`date_time`,
`author`,
`action`,
`table_name`,
`record_id`,
`conversation_id`,
`transaction_id`
) VALUES (
@when,
author,
'orphaned',
'item',
item_id,
conversation_id,
transaction_id
);
END IF;
END IF;
SELECT
0 AS `RETURNED_SQLSTATE`,
0 AS `MYSQL_ERRNO`,
'Item unlinked' AS `MESSAGE_TEXT`,
1 as `ROW_COUNT`;
COMMIT;
END;
更新:根本问题在于第一个 SELECT 语句:
SELECT `id` FROM `item_contains`
WHERE `parent_id` = parent_id
AND `child_id` = item_id
我假设左侧 parent_id
是来自 item_contains
的,右侧 parent_id
是存储过程参数。我误解了。两者都被解释为存储过程参数。解决方案是为表设置别名并通过别名引用字段,如下所示:
SELECT ic.id FROM item_contains AS ic
WHERE ic.parent_id = parent_id
AND ic.child_id = item_id
但是:原来的问题仍然存在:
我可以在 EXIT HANDLER
中添加一些内容来告诉我存储过程中的何处引发了错误吗?
最佳答案
所有 SELECT ... INTO
语句必须仅返回一行。
例如,以下代码可能返回多于 1 条记录:
SELECT `id`
FROM `item_contains`
WHERE `parent_id` = parent_id
AND `child_id` = item_id
INTO @deleted;
您可以调试将结果存储在另一个变量中的语句并选择
:
SELECT count(*)
FROM `item_contains`
WHERE `parent_id` = parent_id
AND `child_id` = item_id
INTO @supposed_to_delete;
SELECT @supposed_to_delete; /*you will see the value after execute*/
另一种确保只有一条记录的方法(不推荐)是添加限制
SELECT `id`
FROM `item_contains`
WHERE `parent_id` = parent_id
AND `child_id` = item_id
LIMIT 1 /* <-- force to return only one record */
INTO @deleted;
关于mysql - 在 MySQL 存储过程的退出处理程序中获取失败语句的 SQL,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47288125/