Optional join

From: "Slawek Jarosz" <Jarosz(dot)S(at)ems-t(dot)ca>
To: pgsql-sql(at)postgresql(dot)org
Subject: Optional join
Date: 2003-08-14 14:40:02
Message-ID: sf3b6707.030@ems-t.ca
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Hi,

I trying to write a query that will join 2 tables. Here's the concept:
Table 1: table1, primary key pk1
Table 2: table2, primary key pk2

One of the fields (f2) in table2 contains either the primary key of table1 or a NULL value. So normally a pretty basic query:

SELECT table1.*, table2.pk2 FROM table1, table2 WHERE table2.f2 = table1.pk1;

BUT what I would like to do is show all records of Table 1 even if there is no match in Table 2. Meaning that the reults could be
table1... table2.pk2
table1... NULL

Doable?

Thanks.

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