Constraint « Table « Oracle PL/SQL Tutorial

6.10.1.Adding a Constraint
6.10.2.Add constaint for a date type column: larger than a certain date
6.10.3.Adding a 'NOT NULL' Constraint
6.10.4.The database automatically assigns a name to the constraint
6.10.5.Dropping a Constraint
6.10.6.Disabling a Constraint
6.10.7.Add CASCADE to the end of a DISABLE CONSTRAINT clause
6.10.8.Enabling a Constraint
6.10.9.You can also choose to apply a constraint to new data only by specifying ENABLE NOVALIDATE.

6.10.10.Deferred Constraints
6.10.11.How to drop a constaint
6.10.12.Violate a constraint
6.10.13.Cascade constraints