diff --git a/doc/src/sgml/queries.sgml b/doc/src/sgml/queries.sgml index 5c48ae1d625df6d2f08ae4afd767c155bcdde124..c427303db3a7135ef6a982c0d9fac0d0ce6a444f 100644 --- a/doc/src/sgml/queries.sgml +++ b/doc/src/sgml/queries.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/queries.sgml,v 1.40 2007/01/09 02:14:10 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/queries.sgml,v 1.41 2007/01/09 16:59:20 tgl Exp $ --> <chapter id="queries"> <title>Queries</title> @@ -1262,6 +1262,13 @@ SELECT a, b FROM table1 ORDER BY a + b, c; <literal>DESC</> order, and <literal>NULLS LAST</> otherwise. </para> + <para> + Note that the ordering options are considered independently for each + sort column. For example <literal>ORDER BY x, y DESC</> means + <literal>ORDER BY x ASC, y DESC</>, which is not the same as + <literal>ORDER BY x DESC, y DESC</>. + </para> + <para> For backwards compatibility with the SQL92 version of the standard, a <replaceable>sort_expression</> can instead be the name or number diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0af1fbb07a4b882118ffff65648c6e1336447c18..f77b805118d139b3a54d3b61886ea28a0df919f3 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.95 2007/01/09 02:14:10 tgl Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.96 2007/01/09 16:59:20 tgl Exp $ PostgreSQL documentation --> @@ -644,13 +644,6 @@ HAVING <replaceable class="parameter">condition</replaceable> <synopsis> ORDER BY <replaceable class="parameter">expression</replaceable> [ ASC | DESC | USING <replaceable class="parameter">operator</replaceable> ] [ NULLS { FIRST | LAST } ] [, ...] </synopsis> - <replaceable class="parameter">expression</replaceable> can be the - name or ordinal number of an output column - (<command>SELECT</command> list item), or it can be an arbitrary - expression formed from input-column values. - </para> - - <para> The <literal>ORDER BY</literal> clause causes the result rows to be sorted according to the specified expression(s). If two rows are equal according to the leftmost expression, they are compared @@ -659,6 +652,13 @@ ORDER BY <replaceable class="parameter">expression</replaceable> [ ASC | DESC | an implementation-dependent order. </para> + <para> + Each <replaceable class="parameter">expression</replaceable> can be the + name or ordinal number of an output column + (<command>SELECT</command> list item), or it can be an arbitrary + expression formed from input-column values. + </para> + <para> The ordinal number refers to the ordinal (left-to-right) position of the result column. This feature makes it possible to define an @@ -717,6 +717,12 @@ SELECT name FROM distributors ORDER BY code; on whether the operator is a less-than or greater-than operator. </para> + <para> + Note that ordering options apply only to the expression they follow; + for example <literal>ORDER BY x, y DESC</> does not mean + the same thing as <literal>ORDER BY x DESC, y DESC</>. + </para> + <para> Character-string data is sorted according to the locale-specific collation order that was established when the database cluster