How to invalidate foreign keys in oracle

In Oracle, you can use the alter table statement with disable constraint to invalidate the foreign key. The syntax is "alter table table name disable constraint foreign key name;"; if the foreign key fails, the link between the two table data will be cancelled. one or more columns.

The operating environment of this tutorial: Windows 10 system, Oracle 11g version, Dell G3 computer.

How oracle invalidates foreign keys

Invalidate foreign keys:

alter table tableName disable constraint 外键名称;

We first create a foreign key named fk_supplier through the following code:

In this example, a primary key named supplier_pk is created on the supplier table. It contains only one field - supplier_id field. Then, we created a foreign key named fk_supplier on the products table. The supplier_id field of the products table refers to the supplier_id field of the suppliers table.

If you want to delete this foreign key, you can execute the following command:

Expand knowledge:

Enable foreign key Key recovery:

alter table tableName enable constraint 外键名称;

Delete foreign key:

alter table tableName drop constraint 外键名称;

Recommended tutorial: "Oracle Video Tutorial"

The above is the detailed content of How to invalidate foreign keys in oracle. For more information, please follow other related articles on the PHP Chinese website!