Question on Update table

Question

DECLARE
vid number;
Hello,
i need to update a table which already has data in it. we added another coulmn which will be a unique key. This is basically a sequence. how do i upate the existing table with the data for this new column to generate the sequence.
i wrote the following code: but its creating new rows with the new sequence i want to upate the existing rows with the sequnce for the newly added column.
declare
vid number;
BEGIN
for c in ( select * from test)
loop
select test_SEQ.nextval into vid from dual;
insert into test (SEQ_NUM)
values (vid);
end loop;
commit;
end;
could someone help.
Thanks.

Answer 1

Hi,
789287 wrote:
DECLARE
vid number;
Hello,
i need to update a table which already has data in it. we added another coulmn which will be a unique key. This is basically a sequence. how do i upate the existing table with the data for this new column to generate the sequence.
i wrote the following code: but its creating new rows with the new sequence i want to upate the existing rows with the sequnce for the newly added column.INSERT means create new rows. You don't want to INSERT here.
UPDATE means to change values on existing rows. You want to UPDATE here.
declare
vid number;
BEGIN
for c in ( select * from test)
loop
select test_SEQ.nextval into vid from dual;
insert into test (SEQ_NUM)
values (vid);
end loop;
commit;
end;
could someone help.
Thanks.Try this:
UPDATE  test
SET     seq_num = test_seq.NEXTVAL;You don't need PL/SQL for this, but if you need PL/SQL for some other reason, the UPDATE statement above will work in PL/SQL
Edited by: Frank Kulash on Oct 20, 2011 3:45 PM