Hi,
we have used alter table to change the constraint in on delete cascade. there is two option. what is different between both of them.
Example:
1)Alter table t3 add constraint t2_F foreign key (id) references t2(id,column2,column3) on delete cascade ;
or
2)Alter table t3 add constraint t2_F foreign key (id) references t2 on delete cascade ;
i know first one that particular column will set to on delete cascade.
What is the use of second one in this case we are not using column name in "foreign key (id) references t2 on delete cascade ;"