On Sun, Jan 8, 2012 at 7:13 PM, 邓尧 <torshie@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.
