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diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html index aff8e80df06..2ef4f1eceee 100644 --- a/doc/src/FAQ/FAQ.html +++ b/doc/src/FAQ/FAQ.html @@ -1224,21 +1224,26 @@ Lobby your company to join W3C, see http://www.w3.org/Consortium <H4><A name="4.24">4.24</A>) How do I do an <I>outer</I> join?<BR> </H4> - <P>PostgreSQL 7.1 and later supports outer joins. Here is an - example:</P> + <P>PostgreSQL 7.1 and later supports outer joins. Here are two + examples:</P> +<PRE> + SELECT * + FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col); +</PRE> +or <PRE> SELECT * FROM t1 LEFT OUTER JOIN t2 USING (col); </PRE> - This will join t1.col to t2.col, and return any unjoined rows in t1 - with <SMALL>NULL</SMALL> values for t2 columns. A - <SMALL>RIGHT</SMALL> join would return unjoined rows of table t2. A - <SMALL>FULL</SMALL> join would return unjoined rows from t1 and t2. - The word <SMALL>OUTER</SMALL> is optional and is assumed in - <SMALL>LEFT</SMALL>, <SMALL>RIGHT</SMALL>, and <SMALL>FULL</SMALL> - joins. Ordinary joins are called <SMALL>INNER</SMALL> joins.<BR> - <BR> - In previous releases, outer joins can be simulated using + These identical queries join t1.col to t2.col, and return any + unjoined rows in t1. A <SMALL>RIGHT</SMALL> join would return + unjoined rows of table t2. A <SMALL>FULL</SMALL> join would return + unjoined rows from t1 and t2. The word <SMALL>OUTER</SMALL> is + optional and is assumed in <SMALL>LEFT</SMALL>, + <SMALL>RIGHT</SMALL>, and <SMALL>FULL</SMALL> joins. Ordinary joins + are called <SMALL>INNER</SMALL> joins.</P> + + <P>In previous releases, outer joins can be simulated using <SMALL>UNION</SMALL> and <SMALL>NOT IN</SMALL>. For example, when joining <I>tab1</I> and <I>tab2,</I> the following query does an <I>outer</I> join of the two tables:<BR> |