haritha


{ City } ongole
< Country > india
* Profession * student
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Questions / { haritha }
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can we update a view which is created from two tables

11 SQL PLSQL 30886




Answers / { haritha }

Question { Wipro, 131887 }

What are constraints? Explain different types of
constraints?


Answer

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

Question { Wipro, 131887 }

What are constraints? Explain different types of
constraints?


Answer

Including these it also contains check constraint.
check constraint:-It specifies a range of values witn in
which the attribute should take

Is This Answer Correct ?    101 Yes 47 No


Question { 5649 }

What is Remote Procedure Call?


Answer

Remote procedure call is used to mount remote clients to
the servers.

Is This Answer Correct ?    2 Yes 0 No

Question { ABC, 172542 }

What is the difference between join and union.


Answer

we can join two tables by 'join' if they have common
field.we can union two tables irrespective of common field.

Is This Answer Correct ?    316 Yes 148 No