当前位置：网站首页>MySQL Database Constraints

MySQL Database Constraints

2022-07-06 13:14:00 【Born like summer flowers LXM】

The definition of constraints

Insert picture description here

Classification of constraints

Insert picture description here

Primary key constraint

A primary key composed of multiple columns ： Combined the primary key
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here

The primary key grows by itself

Insert picture description here

Uniqueness constraint

Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here

Non null and default constraints

Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here

Default constraint

Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here

Check constraint

Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here

Foreign key constraints （ Most used constraints ）

Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Write the primary key first and then the foreign key
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here

Comprehensive practice

Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
The database model can use this software
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here
Insert picture description here

原网站

版权声明
本文为[Born like summer flowers LXM]所创，转载请带上原文链接，感谢
https://yzsam.com/2022/02/202202131450066593.html

边栏推荐

猜你喜欢

随机推荐