Difference between primary key and unique key ?
Answer Posted / lucky
Primary key not accepts to null values in database, but
uniqe key accepts to the null values in database.
Each table having only one PRIMARY KEY.And my contain many
UNIQUE KEYS.
PRIMARY KEY is identity of each row. UNIQUE KEY also
identity of each row.
BOTH keys will not contain repeated value.
BUT UNIQUE KEY will contain NULL value but PRIMAY key will
not contain NULL value.
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
What is a package ? What are the advantages of package ?
What is a system tablespace?
What is a data dictionary and how can it be created?
Explain how are indexes update?
How to connect to a local oracle 10g xe server?
List the types of joins used in writing subqueries?
Explain the use of control file?
What is a static data dictionary in oracle?
How to create an oracle database?
What privilege is needed for a user to query tables in another schema?
Please explain drop constraint oracle?
How to set a transaction to be read only in oracle?
what is dynamic SGA and static SGA
How do I limit the number of oracle database connections generated by weblogic server?
How to use "in out" parameter properly?