INSERT of two records into different tables (pk value from first to second)

Question

Hi there!
Have probably stupid question
Need to insert one record into table with primary key and then insert into other table record with value of primary key field from first record
How can I do it?
Thanks a lot!!!

Answer 1

You have several possibilities. Most easiest one is listed first :)
SQL> create table a (a number);
Table created.
SQL> alter table a add constraint a_pk primary key (a);
Table altered.
SQL> create table b (a number);
Table created.
SQL> alter table b add constraint  b_a_fk foreign key (a) references a(a);
Table altered.
SQL> insert into a values (0);
1 row created.
SQL> insert into b values (0);
1 row created.Though that may not help always, so the next possibility maybe just using sequence with nextval and currval (currval can be used only in the same session and only after you have issued at least one nextval)
SQL> create sequence a_seq;
Sequence created.
SQL>  insert into a values (a_seq.nextval);
1 row created.
SQL> insert into b values (a_seq.currval);
1 row created.And you can use also famous returning clause. It is a bit easier to show that in the pl/sql block than pure SQL.
SQL> declare
  2   v number;
  3  begin
  4   insert into a values (a_seq.nextval) returning a into v;
  5   insert into b values (v);
  6  end;
  7  /
PL/SQL procedure successfully completed.And at last contents of the tables :)
SQL> select * from b;
         A
         0
         1
         2
SQL> select * from a;
         A
         0
         1
         2Gints Plivna
http://www.gplivna.eu