Interested to Buy Any Domain ? << Click Here >> for more details...
When we can declare a column as Unique and Not Null both at
the same time. What is the use pf Primary Key then?
- 2 Answers
- 17801 Views
- Accenture, Unisoft Infotech, I also Faced
- E-Mail Answers
Answer Posted / swapna
The concept of adding an unique key and not null constraint
to a column as well as adding as unique index to it , you
will assume to get the benefits of adding an primary key
to that column.
But use it for the purpose of referential integrity will
not allow to do so.
That's what PK is so useful. You will use it for
normalization purpose.
| Is This Answer Correct ? | 12 Yes | 6 No |
Post New Answer View All Answers
what is recursive stored procedure? : Sql dba
What is scope and visibility in PL/SQL?
What is normalization? How many normalization forms are there?
Does mysql support pl sql?
How to test for null values?
When sql appeared?
Is join an inner join?
How do you create a unique index?
What are different types of queries in sql?
What is the use of stored procedures?
How can you create an empty table from an existing table?
explain advantages of myisam over innodb? : Sql dba
What is the difference between mdf and ndf files?
what is sql profiler? : Sql dba
What is primary key secondary key alternate key candidate key?
