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
- 17820 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 has stored procedures in sql?
how can we know the number of days between two given dates using mysql? : Sql dba
How do sql databases work?
What do you think about pl/sql?
What are reports usually used for?
Which join condition can be specified using on clause?
What is thread join () in threading?
what is the difference between mysql_fetch_object and mysql_fetch_array? : Sql dba
What is the syntax to add a record to a table?
name 3 ways to get an accurate count of the number of records in a table? : Sql dba
What is tuple in sql?
Name some usages of database trigger?
What is the use of desc in sql?
What are the possible values that can be stored in a boolean data field?
What is dba in sql? : SQL DBA
