MariaDB 升级（从 10.1 到 10.4.6）后触发器停止运行

Question

自从我升级到 MariaDB 10.4.6 后，我的 BEFORE INSERT 触发器之一出现问题。

触发器定义如下（去掉无用的部分）

 CREATE TRIGGER `trg_bins_stock`
 BEFORE INSERT ON `stock`
 FOR EACH ROW
 BEGIN  

DECLARE maxprice DOUBLE DEFAULT NULL;
DECLARE errormsg VARCHAR(255) DEFAULT '';

select  MAX(price)  into maxprice 
FROM view_articles
where view_articles.id_ref = NEW.id_ref;

IF (maxprice is null) THEN

  SET errormsg = CONCAT("INSERT ERROR : missing line in view_articles [art ref :  ",  NEW.id_ref ,  "]");

  SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = errormsg; 

END IF;

END

当插入“stock”表时，即使我不应该得到自定义错误，例如消息“INSERT ERROR : missing line in view_articles [art ref:11757]”

查询：

select  MAX(price)  
    FROM view_articles
    where view_articles.id_ref = 11757;

不返回 null，所以我不应该触发这个错误。

到目前为止我测试过的内容：

• 触发器中“maxprice”的值实际上是 NULL（因此 if 子句没有问题）。
• 如果我修改触发器以在选择查询中将 11757 代替 NEW.id_ref，则 maxprice 不为 NULL。
• 如果我创建一个类似于我的视图“view_articles”的表“table_articles”，并执行 INSERT INTO table_articles SELECT * FROM view_articles，然后修改我的触发器以使用表而不是 看来，maxprice 也不为空。

附加信息：

Sql 模式设置为 'NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION' 。 创建视图、表、触发器以及用于插入表的用户是相同的，并且具有“授予 . 的所有权限”。 在 debian 9 上使用 mariadb 10.4.6（按照升级说明页面从 10.1 升级）进行测试，并在 Windows 机器上全新安装相同版本，并从转储中加载 db。

编辑更多信息、测试和解决方法： view_articles 定义（简化）如下：

CREATE VIEW view_articles  AS 
 SELECT articles2.id_ref as id_ref, articles2.pricing as price
  from articles2 
 UNION 
SELECT articles.id_article as id_ref, articles.price as price 
  from articles

如果我直接在触发器中使用此语句代替视图，我仍然会遇到同样的问题，但这有效：

IF(new.id_ref <0) THEN 
 select MAX(articles2.pricing) INTO maxprix    
      from articles2  WHERE articles2.id_ref =  new.id_ref ;
ELSE 
 select MAX(articles.price) INTO maxprix 
 from articles WHERE articles.id_article = new.id_ref ;
END IF;

那么，现在是否禁止在触发器中使用带有 UNION 子句的视图？或者这是一个错误？

我对我的解决方法并不十分满意，因为有一天我可能在“文章”表中有负 ID，而在“文章 2”中可能有正 ID，即使现在不是这样。所以我仍然欢迎更优雅的解决方案。

Answer 1

这是一个影响 MariaDB 10.2、10.3 和 10.4 版本的错误。必须解决它，直到修复错误。 MariaDB 错误跟踪链接：https://jira.mariadb.org/browse/MDEV-19975

Answer 2

我无法重现该问题：

MariaDB [(none)]> USE `_`;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

MariaDB [_]> SELECT VERSION();
+----------------+
| VERSION()      |
+----------------+
| 10.4.6-MariaDB |
+----------------+
1 row in set (0.000 sec)

MariaDB [_]> SELECT @@global.sql_mode, @@session.sql_mode\G
*************************** 1. row ***************************
 @@global.sql_mode: STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
@@session.sql_mode: STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
1 row in set (0.000 sec)

MariaDB [_]> DROP VIEW IF EXISTS `view_articles`;
Query OK, 0 rows affected (0.000 sec)

MariaDB [_]> DROP TABLE IF EXISTS `articles`, `stock`;
Query OK, 0 rows affected (0.002 sec)

MariaDB [_]> CREATE TABLE IF NOT EXISTS `stock`(
    ->   `id_ref` INT NOT NULL
    -> );
Query OK, 0 rows affected (0.001 sec)

MariaDB [_]> CREATE TABLE IF NOT EXISTS `articles`(
    ->   `id_article` INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
    ->   `price` NUMERIC(10, 2)
    -> );
Query OK, 0 rows affected (0.001 sec)

MariaDB [_]> CREATE VIEW `view_articles`  AS
    -> SELECT `articles`.`id_article` `id_ref`, `articles`.`price`
    -> FROM `articles`;
Query OK, 0 rows affected (0.000 sec)

MariaDB [_]> DELIMITER //

MariaDB [_]> CREATE TRIGGER `trg_bins_stock` BEFORE INSERT ON `stock`
    -> FOR EACH ROW
    -> BEGIN
    ->   DECLARE `maxprice` NUMERIC(10, 2) DEFAULT NULL;
    ->   DECLARE `errormsg` VARCHAR(255) DEFAULT '';
    -> 
    ->   SELECT MAX(`price`) INTO `maxprice`
    ->   FROM `view_articles`
    ->   WHERE `view_articles`.`id_ref` = NEW.`id_ref`;
    -> 
    ->   IF (`maxprice` IS NULL) THEN
    ->     SET `errormsg` := CONCAT('INSERT ERROR: missing line in view_articles [art ref: ',  NEW.`id_ref` ,  ']');
    ->     SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = `errormsg`; 
    ->   END IF;
    -> END//
Query OK, 0 rows affected (0.000 sec)

MariaDB [_]> DELIMITER ;

MariaDB [_]> INSERT INTO `articles`
    -> VALUES (11757, 2000);
Query OK, 1 row affected (0.000 sec)

MariaDB [_]> SELECT `id_article`, `price`
    -> FROM `articles`;
+------------+---------+
| id_article | price   |
+------------+---------+
|      11757 | 2000.00 |
+------------+---------+
1 row in set (0.000 sec)

MariaDB [_]> INSERT INTO `stock`
    -> VALUES (11757);
Query OK, 1 row affected (0.001 sec)

MariaDB [_]> SELECT `id_ref`
    -> FROM `stock`;
+--------+
| id_ref |
+--------+
|  11757 |
+--------+
1 row in set (0.000 sec)

MariaDB [_]> INSERT INTO `stock`
    -> VALUES (1);
ERROR 1644 (45000): INSERT ERROR: missing line in view_articles [art ref: 1]