Oracle/PLSQL: Disable a foreign key
Learn how to disable a foreign key in Oracle with syntax and examples.
Once you have created a foreign key in Oracle, you may encounter a situation where you are required to disable the foreign key. You can do this using the ALTER TABLE statement in Oracle.
The syntax to disable a foreign key in Oracle/PLSQL is:
ALTER TABLE table_name DISABLE CONSTRAINT constraint_name;
If you had created a foreign key as follows:
CREATE TABLE supplier ( supplier_id numeric(10) not null, supplier_name varchar2(50) not null, contact_name varchar2(50), CONSTRAINT supplier_pk PRIMARY KEY (supplier_id) ); CREATE TABLE products ( product_id numeric(10) not null, supplier_id numeric(10) not null, CONSTRAINT fk_supplier FOREIGN KEY (supplier_id) REFERENCES supplier(supplier_id) );
In this example, we've created a primary key on the supplier table called supplier_pk. It consists of only one field - the supplier_id field. Then we've created a foreign key called fk_supplier on the products table that references the supplier table based on the supplier_id field.
If we then wanted to disable the foreign key called fk_supplier, we could execute the following command:
ALTER TABLE products DISABLE CONSTRAINT fk_supplier;