Oracle Constraints

Constraints:
  • The Oracle CONSTRAINT clause allows you to restrict the data that is entered into a column to ensure that it is valid or that it meets certain conditions.
  • The Oracle Server uses constraints to prevent invalid data entry into tables. The constraints store the validate data and without constraints we can just store invalid data.
          1. Primary Key Constraint
          2. Foreign Key Constraint
          3. Unique Constraint
          4. Not null Constraint
          5. Check Constraint