Add, delete, modify, and delete constraints in Oracle

Add Constraints

SQL> alter table customer add constraint cardunique unique (cardId );

Delete Constraints

SQL> alter table customer drop constraint addresscheck;

When deleting a primary key, the cascade option must be included.

SQL> alter table customer primary key cascade;

Add primary key

SQL> alter table customer add constraint pkkey primary key (customerId );

View Constraints

SQL> select constraint_name, table_name, r_owner, r_constraint_name

2 from all_constraints where table_name = 'goods 'and table_name = 'customer ';