On Dec 10, 2011, at 11:03, Richard Klingler <rich...@klingler.net> wrote:
> Good day... > > I'm trying to build a query for PGSQL 9.1 where a table has two > references with only one being used depending of the type of entry.. > > For example, the table has following simplified structure: > > portid primary key > port2node index to table node > port2card index to table card > > So how can I do a conditional FROM clause in the query depending on the > column port2node and port2card? > If port2card is Null or 0 I don't want it in the FROM clause as the > query will return unneccessary duplicate > row...the same goes for port2node being Null or 0... > > > thanx in advance > richard > > Two options (one of which may not work for you). 1. Write two queries, one for each table, and union the results. 2. Use LEFT JOINs (somehow...) David J. -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
