Answer Posted / reva ram sahu
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 ? | 4 Yes | 0 No |
Post New Answer View All Answers
How to use “drop” keyword in sql server and give an example?
Explain unique key in sql server?
if you encounter this kind of an error message, what you need to look into to solve this problem? : Sql server database administration
Are there any preferred steps that need to be taken care of before starting the installation of sql server 2000?
What does indexation mean?
What are the acid properties?
What is the syntax to execute the sys.dm_db_missing_index_details? : sql server database administration
How to create a dynamic cursor with the dynamic option?
What is ddl command?
How to how to convert numeric expression data types using the convert() function??
Explain the different types of joins?
how you can configure a running aggregate in SSRS?
How can we solve concurrency problems?
Sql server reporting services vs. Crystal reports.
What is an indexing strategy?