On Apr 29, 11:08 am, md <mardahl2...@yahoo.com> wrote:
> This is what I wish I could to do.
>
> insert into table_x (a, b, c)
> values(1, 2, 3)
> where not exist (select * from table_x where a = 2);

(BTW it helps to spell EXISTS correctly. Best is to copy and paste the
query you tried instead of retyping it because something always goes
wrong when manually retyping.)
>
> Thank you.
>
you are just so close to seeing the answer, try this:
drop table ejp;

create table ejp as
select 3 a,2 b,1 c from dual ;

select * from ejp ;

insert into ejp (a, b, c)
select 2, 2, 3 from dual
where not exists
(select * from ejp where a = 2);

select * from ejp ;


insert into ejp (a, b, c)
select 1, 2, 3 from dual
where not exists
(select * from ejp where a = 2);

select * from ejp ;

And the results:
Table dropped.
Table created.

A B C
---------- ---------- ----------
3 2 1


1 row selected.
1 row created.

A B C
---------- ---------- ----------
3 2 1
2 2 3


2 rows selected.
created.

A B C
---------- ---------- ----------
3 2 1
2 2 3


2 rows selected.

(sorry for the separate script/output. I ran this from Toad.

HTH,
Ed