Delete a foreign key constraint when you want to remove the requirement to enforce referential integrity.
如果想要移除对强制引用完整性的要求,则可删除外键约束。
A relationship that does not enforce referential integrity appears as a thin line between the common fields supporting the relationship.
不实施参照完整性的关系在支持该关系的公共字段之间显示为细线。
If the line appears dotted, the DBMS does not enforce referential integrity for the relationship when rows are added or modified in the foreign-key table.
如果为点线,则当在外键表中添加或修改行时,DBMS不强制关系的引用完整性。
Triggers are often created to enforce referential integrity or consistency among logically related data in different tables.
触发程序通常是用来强制执行参考完整性或不同资料表间逻辑上相关之资料的一致性。
Triggers are often created to enforce referential integrity or consistency among logically related data in different tables.
触发程序通常是用来强制执行参考完整性或不同资料表间逻辑上相关之资料的一致性。
应用推荐