What is the difference between the Primary and Foreign key?
Answer Posted / dhirendra
Primary Key: This is a constraint which is always unique &
not null.
Foreign Key: This is a constraint which is just opposite to
Primary key. It can be not Null & can accept duplicate value
as well. Foreign key points to same table's primary key or
another table's primary key to make a relationship.
| Is This Answer Correct ? | 12 Yes | 2 No |
Post New Answer View All Answers
Are there any features that are decommissioned in 11g that are not present in 11g?
explain advantages of innodb over myisam. : Sql dba
How do I get sql certification?
What is pl sql block structure?
What are literals in sql server?
How to pronounce postgresql?
define sql delete statement ? : Sql dba
What is the difference between numeric and autonumber?
Can ddl statements be used in pl/sql?
How to get list of all tables from a database?
Why does sql need a server?
What is the difference between sql, mysql and sql server?
How do I add a database to sql?
What is loop in pl sql?
What do you mean by rowid?