How to update parent and child tables while updating parent table

Question

I have a parent table EMPLOYEE which includes columns (sysid, serviceno,employeename...) sysid is Primary key, serviceno is Unique key and I have child table DEPENDENT includes columns (sysid,employee_sysid,name,dob...) here again SYSID is primary key for DEPENDENTS table, employee_sysid is Foreign key of EMPLOYEE table.
Now I want to change SYSID (using sequence) in EMPLOYEE table which need to be update in DEPENDENTS table as well
Note: I have 10000 records in EMPLOYEE table as well as I have 5 more child tables which need to update new SYSID.
please help me

Answer 1

first disable the FOREIGN KEY Constraints.
you can update Parent as well as Child record also with help of trigger.
here i am giving you one examlpe..it may help u.
create table parent(id number primary key,name varchar2(100))
create table child_1(id number primary key,p_id number,dob date,
CONSTRAINT FK_id FOREIGN KEY (p_id) REFERENCES parent (ID))
create table child_2(id number primary key,p_id2 number,addr varchar2(1000),
CONSTRAINT FK_id2 FOREIGN KEY (p_id2) REFERENCES parent (ID))
insert some test data to parent and child tables.
alter table child_2 disable constraint FK_id2
alter table child_1 disable constraint FK_id2
CREATE OR REPLACE TRIGGER delete_child
BEFORE UPDATE ON parent
FOR EACH ROW
BEGIN
UPDATE CHILD_1
SET P_ID=:NEW.ID
WHERE P_ID=:OLD.ID;
UPDATE CHILD_2
SET P_ID2 =:NEW.ID
WHERE P_ID2=:OLD.ID;
END;
then Upadte parent table primary key col and check the child tables.
then enable the constraints...