What are constraints? Explain different types of
constraints?
Answer Posted / haritha
constraint is a rule which can not be voilated by end users.
Different types of constraints are available.They are:-
1)default constraint:-which is used to define a default
value.
2)primary key:-the key which does not allows duplication
and null values.
3)foreign key:-the key used to refer primary key defined
field in another table and it allows duplication.
4)null:-which allows NULL values.
5)not null:-which does not allows NULL values.
6)unique key:-which does not allows duplication but allows
NULL values.
| Is This Answer Correct ? | 283 Yes | 70 No |
Post New Answer View All Answers
How to drop an existing table with "drop table" statements in ms sql server?
What is the difference between cube operator and rollup operator? : SQL Server Architecture
how to control the amount of free space in your index pages? : Sql server database administration
what are candidate key, alternate key and composite key? : Sql server database administration
What are the advantages of policy management?
How to make a column nullable?
What are “phantom rows”?
How can I add Reporting Services reports to my application?
What is user-defined functions? What are the types of user-defined functions that can be created?
Differentiate between SQL and ORACLE joins and write their syntax.
What is the Control Flow in SSIS
What is transaction server implicit?
How to use “drop” keyword in sql server and give an example?
What do you understand by a stored procedure?
What Is Rdbms?