13 | What is CONSTRAINT in SQL and How to use CONSTRAINT as Validator | Oracle PL/SQL Programming
Constraint is a rule to which data must conform
Constraint names are optional
Constraint can be enabled/disabled/dropped
Constraint can be added at the column level or table level
Most Commonly used Constraints are -
Not null
unique
Primary key
Check
Foreign key
13 | What is CONSTRAINT in SQL and How to use CONSTRAINT as Validator | Oracle PL/SQL Programming
#CONSTRAINT #PRIMARYKEY #FOREIGNKEY #NOTNULL #UNIQUE