Mysql在非空字段上插入或更新为空值时不会出错

Question

我有一张 table

CREATE TABLE `devicelist` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `ip` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL,
  `serial` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
  `networkname` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
  `login` varchar(130) COLLATE utf8_unicode_ci DEFAULT NULL,
  `password` varchar(130) COLLATE utf8_unicode_ci DEFAULT NULL,
  `peopleid` int(10) unsigned NOT NULL,
  `deviceid` int(10) unsigned NOT NULL,
  `placeid` int(10) unsigned NOT NULL,
  `stationid` int(10) unsigned NOT NULL,
  `place` text COLLATE utf8_unicode_ci,
  `date` date NOT NULL,
  `active` tinyint(1) NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`),
  KEY `placeid` (`placeid`),
  KEY `stationid` (`stationid`),
  KEY `peopleid` (`peopleid`),
  KEY `deviceid` (`deviceid`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

如您所见，serial 设置为 NOT NULL，
但是当我运行类似

的查询时

UPDATE DeviceList SET serial = NULL WHERE id = 1

输出

1 row affected. ( Query took 0.0079 sec )

为什么要在非空字段中插入空值？
我希望发生错误:D

///********************************* 编辑

我找到答案了
问题出在 sql_mode
https://dev.mysql.com/doc/refman/5.6/en/sql-mode.html#sql-mode-strict
我的 sql_mode 默认为空
我通过

将其更改为 STRICT_ALL_TABLES

SET GLOBAL sql_mode='STRICT_ALL_TABLES'

Answer 1

MySQL 把我今天的一天都搞砸了，所以我只是分享我从中学到的东西。

MySQL 5.6 默认为 NO_ENGINE_SUBSTITUTION。

MySQL 5.7 默认为 ONLY_FULL_GROUP_BY、STRICT_TRANS_TABLES、NO_ZERO_IN_DATE、NO_ZERO_DATE、ERROR_FOR_DIVISION_BY_ZERO，NO_AUTO_CREATE_USER，NO_ENGINE_SUBSTITUTION。

如本 page 所述来自 MySQL 引用手册，

MySQL installation programs may configure the SQL mode during the installation process. For example, mysql_install_db creates a default option file named my.cnf in the base installation directory.