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
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
Constraints are the constraints which can provide on the
column data.The types of constraints are
1).Domain Integrity constraints
2).Entity Integrity constraints
3).Referential Integrity constraints
these are the constarints or codes which an organisation
has to abide by. Not necessarily does any one have to abide
by these, however there are many biles like that can kinda
get peopel to abide by them u get me blud. Dun now this is
dab real macoy doe.
Vote YES for dis 1 if u r a real G u get me.
All ady everyday 2K8 get 2 know.
i have 4 tables.. T1, T2, T3, T4..
these tables have the same structure and they store the
information entered in different years..
T1 stored 2002, T2 stored 2003, T3 stored 2004 and T4 stored
i want to copy contents in T1 to T2, T2 to T3, T3 to T4 and
T4 to T1..
how do i do that? Temp tables cannot be used..