problem with foreign key in oracle 9i?

Question

i have two tables emp_master,emp_hw
emp_master.empno is primary key and emp_hw.empno is foreing key from emp_master

using jsp i inserted a value to emp_hw.empno ( insert into emp_hw values (' ');) a null value for which corresponding parent key in the table emp_master NOT THERE.
so i should get the error thet PARENT KEY NOT FOUND, but the non parent key value is inserted into emp_hw.empno
so this is violating the foreign key constraint.

if i am inserting same quary in sql this query is showing the error , only by using jsp is prob

what can i do
i should get that ereor and non-parent key should not be inserted

is this prob b coz of jsp ?

Answer 1

Not entirely sure what your exact problem is but 1) a null value in a foreign key column doesn't cause a parent key not found. It will only validate that the parent is valid when you insert an actual value. 2) at a guess, the constraint is set to check at the end of the transaction, not the end of the statement and the jsp is issuing a commit between statements, that's why your statement works in SQL Plus but not jsp.

Answer 2

once you ran the installer, did you tell it to create your first database? in case you probably did no longer, there is not any database created; as a result, no username and password. in case you probably did create one, protection supervisor will up and asks you to specify device and inner account passwords at minimum.

Answer 3

make it as unique key in both table