Difference between primary key and unique key ?

Answer Posted / vitthal parkar

Unique key Primary key
1. Can have null value 1. Can not have null value
2.Table can have multiple 2. Table Can have multiple unique
Unique keys keys
3Single column at a time 3. May be combination of one or
or more columns

Is This Answer Correct ?    35 Yes 58 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What are the advantages of oracle 12c?

563


What is a schema in oracle?

555


What are the attributes that are found in a cursor?

657


What is the dynamic sql in oracle?

610


Is oracle an open source?

642






How to create a temporary table in oracle?

698


What do the 9i dbms_standard.sql_txt() and dbms_standard.sql_text() procedures do?

4028


What is the implicit cursor in oracle?

579


What happens if the imported table already exists?

553


what are bitmap indexes? How does they work?

1725


What are the different types of synonyms?

607


hello friends Im doing my final year engineering in B.Tech.. one of uncle said he can provide job in his company if im good in database management. but i have only basic knowledge about database, so like to join database management course in good intuition. so friends kindly help me to get good intuition because its my future.

1765


Does oracle partitioning improve performance?

559


Why do we need oracle client?

519


What is Undo Management Advisor in Oracle?

618