Hello sir,

I am trying to add a referential constraint, like this:

alter table t1_name add constraint Constraint_name
foreign key (col_name) references t2_name;

BUT GETTING ERROR:

alter table t1_name add constraint Constraint_name
*

ERROR at line 1:
ORA-02298: cannot validate (GANESH.Constraint_name) - parent keys not found


Can you please tell me the solution.
I want to add this constraint.
What could be the problem.

Waiting for your reply sir,
Krishna