SQL Constraint 1

Which of the  following constraint ,ORACLE  doesn't supports ?

A table can have more than one primary key column .

'CHECK ' constraint checks whether the condition specified in the constraint is satisfied.

What is an integrity constraint is a rule ?

Which of the following statements are true about composite primary key ?

Which of the statements are true about primary key ?


Table t2 has also two column C1 and C2. How to declare C2 as Foreign Key which should point Primary Key of t1

What is Foreign key with ON DELETE CASCADE ?

We cannot disable a primary key or unique key if foreign keys that are enable reference it.

How to disable all the referenced foreign keys and the primary or unique key ?