Re: Delete child-parent records???????

Originally posted by Divya
> Hi Tony,
> Thanks for your help....
>
> For the ON DELETE CASCADE...Can you just show me a simple example to
> explain this better?
>
>

OK:-

SQL> create table parent( parent_id number primary key, parent_name SQL> varchar2(10) );

Table created.

SQL> create table child( child_id number primary key, child_name SQL> varchar2(10),
  2 parent_id number,
  3 constraint child_parent_fk foreign key (parent_id)   references parent
  4 on delete cascade
  5* );

Table created.

SQL> insert into parent values (1,'Fred');

1 row created.

SQL> insert into parent values (2,'Barney');

1 row created.

SQL> insert into child values (11,'Pebbles',1);

1 row created.

SQL> insert into child values (21,'Bambam', 2);

1 row created.

SQL> select * from parent;

 PARENT_ID PARENT_NAM
---------- ----------

         1 Fred
         2 Barney

SQL> select * from child;

  CHILD_ID CHILD_NAME PARENT_ID
---------- ---------- ----------

        11 Pebbles             1
        21 Bambam              2

SQL> delete parent where parent_id=2;

1 row deleted.

SQL> select * from child;

  CHILD_ID CHILD_NAME PARENT_ID
---------- ---------- ----------

        11 Pebbles 1

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