为什么MySQL允许将NOT NULL列更新为NULL? [英] Why does MySQL allow to update a NOT NULL column to NULL?

问题描述

我正在ubuntu 10.10中运行MySql.我创建了一个名为'employee'的表，该表具有3个字段名称 empno，名称和薪金.插入了几个实体.在此过程的中间，我想将薪金属性更改为'NOT NULL'.我将表更改为

I'm running MySql in ubuntu 10.10. I created a table called 'employee' having 3 field names empno, name and salary. Inserted few entities. In the middle of the process i want to change salary attribute as 'NOT NULL'. I Alter the table as

ALTER TABLE employee MODIFY salary int(10) NOT NULL;

查询已执行.我想通过使用命令进行测试，

Query executed. I wanted to test by using command,

UPDATE employee SET salary=NULL;

Query OK, 15 rows affected, 15 warnings (0.06 sec)
Rows matched: 15  Changed: 15  Warnings: 15

还给出了警告" (Code 1048): Column 'salary' cannot be null "(每行重复)

also gave warnings " (Code 1048): Column 'salary' cannot be null "(Repeated for every row)

但是当我看到我的桌子时，所有工资都是零('0').

But when i saw my table , All salaries were Zeros('0').

在WINDOWS XP的MySql中，相同的查询导致错误而不是警告

我同时检查了INNODB和MYISAM引擎，但结果相同. 请帮助我了解处理之外发生的情况.

I checked in both INNODB and MYISAM engines but same Result. Please help me to know what happened beside processing.

推荐答案

对于Ubuntu安装，您不得将SQL_MODE设置为严格".

You must not have SQL_MODE set to strict on you ubuntu installation.

问题

SET SQL_MODE='STRICT_ALL_TABLES'

或添加

SQL_MODE='STRICT_ALL_TABLES'

下的

到Ubuntu上的my.cnf.

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