Eric writes:

>    I can realize this function in the SYBase,but How can i do it in the PostgreSQL?
>
> /****SQL***/
> if not exists(select id from test) insert into test(id) values (280);
> /*********/

I don't know if this is SQL92, but 

insert into test(id) select 280 where not exists(select id from test);

Wed, 06 Jun 2001 18:32:37 -0400
Robert Forsman <thoth@purplefrog.com>
Re: SQL( "if ...exists...),how to do it in the PostgreSQL?