Am Samstag, den 22.01.2005, 11:14 +0100 schrieb Ralph van Etten: > Hoi, > > I searched the archives but couldn't find an answer to this: > > I have a table (simplyfied) > > CREATE TABLE test ( > id INT PRIMARY KEY, > name VARCHAR(250) > ); > > I insert records with > > INSERT INTO test (id, name) > SELECT COALESCE(MAX(id)+1, 1), 'name' FROM test > > Ofcourse this gives problems when two clients are inserting a record at > the same time. (duplicate primary keys) But, i can't use a sequence in my > application (the pk consists of more than just a sequence) > > one solution would be to do a 'LOCK TABLE test IN SHARE MODE' before > inserting. This solves my problem but i'm not sure if its the > best way to deal with this kind of concurrency problems ? Is there a > better way ? Of course. The solution to this problem is inherent to a good database and has therefore been done long long ago ;) See: http://borg.postgresql.org/docs/7.4/static/datatype.html#DATATYPE-SERIAL Regards Tino ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
