On Mon, Jan 9, 2012 at 9:53 AM, Jon Nelson <jnelson+pg...@jamponi.net>wrote:
> On Sun, Jan 8, 2012 at 7:13 PM, 邓尧 <tors...@gmail.com> wrote: > > I have enabled the autocommit feature of psycopg2, and removed all the > > transactions in source code, also changed the sql statement to the > > following: > > > > insert into ACCOUNT(HOME) > > select "v1" as HOME > > where not exists (select 1 from ACCOUNT where HOME = "v1") > > > > Surprisingly, I still got the unique constraint violation error, but much > > fewer than before ( only 3 during the last 3 days). > > Any suggestions? Could it be a bug in psycopg2 or postgresql? > > Presumably, you need to add a distinct. > insert into ... select DISTINCT .... where not exists. > I don't think so. The the statement "select .. as .. where not exists" will never return more than one row. > > > -- > Jon >
