Difference between primary key and unique key ?
Answer Posted / mudigouda patil
PRIMARY KEY
1)TABLE CAN NOT HAVE MORE THAN ONE PRIMARY KEY.
2)PK DOES NOT ALLOW NULL VALUES.
UNIQUE KEY
1)TABLES CAN HAVE MORE THAN ONE UNIQUE KEY.
2)UNIQUE KEY ALLOWS NULL VALUES.
| Is This Answer Correct ? | 0 Yes | 1 No |
Post New Answer View All Answers
Can you have more than one content canvas view attached with a window ?
How to define an external table with a text file?
In SAP ECC 6.0 , under DB02 tcode , Tablespace name to be explain stepy step all the col
How to define a cusotmer as a supplier in ORACLE R12
Explain an exception and its types?
What is the difference between $oracle_base and $oracle_home?
What is data block in Oracle?
What is execute immediate in oracle?
How to start instance with a minimal initialization parameter file?
How to enter a new row into a table interactively?
How to create a table index?
How to get maxsal , minsal, ename department wise in single query
How many anonymous blocks can be defined?
How to view the tablespaces in the current database?
Please explain me all types of Data models. Also give me the details if each model can have other name.for example:schematic data model is also known as conceptual data model and entity relation data model.