what is the difference between primary key & foreign key?
Answer Posted / mathiyarasan
Primary is unique one. Each table has only one primary key.
But not allow null values.
Foreign key is opposite of primary. It is reference of
primary key from another table. It allow Null value. Each
table can have more than one foreign key.
Foreign key is used to link one to another table.
Is This Answer Correct ? | 22 Yes | 7 No |
Post New Answer View All Answers
what is the difference between data migration and production migration.
How to create an oracle testing table?
How to use an explicit cursor without open statements?
Explain parameter file in oracle.
What do you understand by a database object?
What is ceil and floor in oracle?
Explain how are indexes update?
What privilege is needed for a user to insert rows to tables in another schema?
What is sharded cluster?
What is a lookup table in oracle?
Can objects of the same schema reside in different tablespace?
what are the default admin accounts in Oracle 10g ?
How do I call oracle stored procedures that take no parameters?
What is a snapshot in oracle database?
What types of joins are used in writing subqueries?