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
- 17752 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 database migration?
What is difference between table and view?
What are the most important characteristics of pl/sql?
What is indexing in sql and its types?
Is a view faster than a stored procedure?
What is the plv (pl/vision) package offers?
Difference between truncate, delete and drop commands?
what is a control file ? : Sql dba
What is record type in pl sql?
What does rownum mean in sql?
What is before trigger?
What is the difference between mdf and ndf files?
What is the use of primary key?
How many tables can a sql database have?
What is form and report?
