sql外键

When a database table is designed an important factor is to make sure that the table is scalable enough and is normalized at the same time. In order to make sure that the tables are well linked and normalized we use SQL foreign keys.

设计数据库表时，重要的因素是确保该表具有足够的可伸缩性并同时进行规范化。 为了确保表之间的链接和规范化，我们使用SQL外键。

SQL外键 (SQL Foreign Key)

A foreign key is defined by a column that matches a column of another table. The foreign key constraint is used to make sure that data referential integrity is maintained.

外键由与另一个表的列匹配的列定义。 外键约束用于确保保持数据引用完整性。