diff options
Diffstat (limited to 'doc/src/sgml/ref/select.sgml')
| -rw-r--r-- | doc/src/sgml/ref/select.sgml | 102 |
1 files changed, 49 insertions, 53 deletions
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 91388151ad4..475281dd7be 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -95,7 +95,7 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] that is referenced more than once in <literal>FROM</literal> is computed only once, unless specified otherwise with <literal>NOT MATERIALIZED</literal>. - (See <xref linkend="sql-with" endterm="sql-with-title"/> below.) + (See <xref linkend="sql-with"/> below.) </para> </listitem> @@ -105,7 +105,7 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] (Each element in the <literal>FROM</literal> list is a real or virtual table.) If more than one element is specified in the <literal>FROM</literal> list, they are cross-joined together. - (See <xref linkend="sql-from" endterm="sql-from-title"/> below.) + (See <xref linkend="sql-from"/> below.) </para> </listitem> @@ -113,8 +113,7 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] <para> If the <literal>WHERE</literal> clause is specified, all rows that do not satisfy the condition are eliminated from the - output. (See <xref linkend="sql-where" - endterm="sql-where-title"/> below.) + output. (See <xref linkend="sql-where"/> below.) </para> </listitem> @@ -126,8 +125,8 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] values, and the results of aggregate functions are computed. If the <literal>HAVING</literal> clause is present, it eliminates groups that do not satisfy the given condition. (See - <xref linkend="sql-groupby" endterm="sql-groupby-title"/> and - <xref linkend="sql-having" endterm="sql-having-title"/> below.) + <xref linkend="sql-groupby"/> and + <xref linkend="sql-having"/> below.) </para> </listitem> @@ -135,9 +134,7 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] <para> The actual output rows are computed using the <command>SELECT</command> output expressions for each selected - row or row group. (See - <xref linkend="sql-select-list" endterm="sql-select-list-title"/> - below.) + row or row group. (See <xref linkend="sql-select-list"/> below.) </para> </listitem> @@ -146,8 +143,7 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] result. <literal>SELECT DISTINCT ON</literal> eliminates rows that match on all the specified expressions. <literal>SELECT ALL</literal> (the default) will return all candidate rows, including - duplicates. (See <xref linkend="sql-distinct" - endterm="sql-distinct-title"/> below.) + duplicates. (See <xref linkend="sql-distinct"/> below.) </para> </listitem> @@ -168,9 +164,8 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] eliminating duplicate rows. Notice that <literal>DISTINCT</literal> is the default behavior here, even though <literal>ALL</literal> is the default for <command>SELECT</command> itself. (See - <xref linkend="sql-union" endterm="sql-union-title"/>, <xref - linkend="sql-intersect" endterm="sql-intersect-title"/>, and - <xref linkend="sql-except" endterm="sql-except-title"/> below.) + <xref linkend="sql-union"/>, <xref linkend="sql-intersect"/>, and + <xref linkend="sql-except"/> below.) </para> </listitem> @@ -180,7 +175,7 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] returned rows are sorted in the specified order. If <literal>ORDER BY</literal> is not given, the rows are returned in whatever order the system finds fastest to produce. (See - <xref linkend="sql-orderby" endterm="sql-orderby-title"/> below.) + <xref linkend="sql-orderby"/> below.) </para> </listitem> @@ -189,7 +184,7 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] If the <literal>LIMIT</literal> (or <literal>FETCH FIRST</literal>) or <literal>OFFSET</literal> clause is specified, the <command>SELECT</command> statement only returns a subset of the result rows. (See <xref - linkend="sql-limit" endterm="sql-limit-title"/> below.) + linkend="sql-limit"/> below.) </para> </listitem> @@ -199,8 +194,8 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] or <literal>FOR KEY SHARE</literal> is specified, the <command>SELECT</command> statement locks the selected rows - against concurrent updates. (See <xref linkend="sql-for-update-share" - endterm="sql-for-update-share-title"/> below.) + against concurrent updates. (See <xref linkend="sql-for-update-share"/> + below.) </para> </listitem> </orderedlist> @@ -219,8 +214,8 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] <refsect1> <title>Parameters</title> - <refsect2 id="sql-with"> - <title id="sql-with-title"><literal>WITH</literal> Clause</title> + <refsect2 id="sql-with" xreflabel="WITH Clause"> + <title><literal>WITH</literal> Clause</title> <para> The <literal>WITH</literal> clause allows you to specify one or more @@ -336,8 +331,8 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] </para> </refsect2> - <refsect2 id="sql-from"> - <title id="sql-from-title"><literal>FROM</literal> Clause</title> + <refsect2 id="sql-from" xreflabel="FROM Clause"> + <title><literal>FROM</literal> Clause</title> <para> The <literal>FROM</literal> clause specifies one or more source @@ -707,8 +702,8 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] </para> </refsect2> - <refsect2 id="sql-where"> - <title id="sql-where-title"><literal>WHERE</literal> Clause</title> + <refsect2 id="sql-where" xreflabel="WHERE Clause"> + <title><literal>WHERE</literal> Clause</title> <para> The optional <literal>WHERE</literal> clause has the general form @@ -724,8 +719,8 @@ WHERE <replaceable class="parameter">condition</replaceable> </para> </refsect2> - <refsect2 id="sql-groupby"> - <title id="sql-groupby-title"><literal>GROUP BY</literal> Clause</title> + <refsect2 id="sql-groupby" xreflabel="GROUP BY Clause"> + <title><literal>GROUP BY</literal> Clause</title> <para> The optional <literal>GROUP BY</literal> clause has the general form @@ -798,8 +793,8 @@ GROUP BY <replaceable class="parameter">grouping_element</replaceable> [, ...] </para> </refsect2> - <refsect2 id="sql-having"> - <title id="sql-having-title"><literal>HAVING</literal> Clause</title> + <refsect2 id="sql-having" xreflabel="HAVING Clause"> + <title><literal>HAVING</literal> Clause</title> <para> The optional <literal>HAVING</literal> clause has the general form @@ -841,8 +836,8 @@ HAVING <replaceable class="parameter">condition</replaceable> </para> </refsect2> - <refsect2 id="sql-window"> - <title id="sql-window-title"><literal>WINDOW</literal> Clause</title> + <refsect2 id="sql-window" xreflabel="WINDOW Clause"> + <title><literal>WINDOW</literal> Clause</title> <para> The optional <literal>WINDOW</literal> clause has the general form @@ -874,8 +869,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl <para> The elements of the <literal>PARTITION BY</literal> list are interpreted in - much the same fashion as elements of a - <xref linkend="sql-groupby" endterm="sql-groupby-title"/>, except that + much the same fashion as elements of a <link + linkend="sql-groupby"><literal>GROUP BY</literal></link> clause, except that they are always simple expressions and never the name or number of an output column. Another difference is that these expressions can contain aggregate @@ -886,8 +881,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl <para> Similarly, the elements of the <literal>ORDER BY</literal> list are interpreted - in much the same fashion as elements of an - <xref linkend="sql-orderby" endterm="sql-orderby-title"/>, except that + in much the same fashion as elements of a statement-level <link + linkend="sql-orderby"><literal>ORDER BY</literal></link> clause, except that the expressions are always taken as simple expressions and never the name or number of an output column. </para> @@ -1011,8 +1006,9 @@ EXCLUDE NO OTHERS <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's - <xref linkend="sql-select-list" endterm="sql-select-list-title"/> or - <xref linkend="sql-orderby" endterm="sql-orderby-title"/>. These functions + <link linkend="sql-select-list"><command>SELECT</command> list</link> or + <link linkend="sql-orderby"><literal>ORDER BY</literal></link> clause. + These functions can reference the <literal>WINDOW</literal> clause entries by name in their <literal>OVER</literal> clauses. A <literal>WINDOW</literal> clause entry does not have to be referenced anywhere, however; if it is not @@ -1038,8 +1034,8 @@ EXCLUDE NO OTHERS </para> </refsect2> - <refsect2 id="sql-select-list"> - <title id="sql-select-list-title"><command>SELECT</command> List</title> + <refsect2 id="sql-select-list" xreflabel="SELECT List"> + <title><command>SELECT</command> List</title> <para> The <command>SELECT</command> list (between the key words @@ -1119,8 +1115,8 @@ EXCLUDE NO OTHERS </note> </refsect2> - <refsect2 id="sql-distinct"> - <title id="sql-distinct-title"><literal>DISTINCT</literal> Clause</title> + <refsect2 id="sql-distinct" xreflabel="DISTINCT Clause"> + <title><literal>DISTINCT</literal> Clause</title> <para> If <literal>SELECT DISTINCT</literal> is specified, all duplicate rows are @@ -1164,8 +1160,8 @@ SELECT DISTINCT ON (location) location, time, report </para> </refsect2> - <refsect2 id="sql-union"> - <title id="sql-union-title"><literal>UNION</literal> Clause</title> + <refsect2 id="sql-union" xreflabel="UNION Clause"> + <title><literal>UNION</literal> Clause</title> <para> The <literal>UNION</literal> clause has this general form: @@ -1217,8 +1213,8 @@ SELECT DISTINCT ON (location) location, time, report </para> </refsect2> - <refsect2 id="sql-intersect"> - <title id="sql-intersect-title"><literal>INTERSECT</literal> Clause</title> + <refsect2 id="sql-intersect" xreflabel="INTERSECT Clause"> + <title><literal>INTERSECT</literal> Clause</title> <para> The <literal>INTERSECT</literal> clause has this general form: @@ -1265,8 +1261,8 @@ SELECT DISTINCT ON (location) location, time, report </para> </refsect2> - <refsect2 id="sql-except"> - <title id="sql-except-title"><literal>EXCEPT</literal> Clause</title> + <refsect2 id="sql-except" xreflabel="EXCEPT Clause"> + <title><literal>EXCEPT</literal> Clause</title> <para> The <literal>EXCEPT</literal> clause has this general form: @@ -1309,8 +1305,8 @@ SELECT DISTINCT ON (location) location, time, report </para> </refsect2> - <refsect2 id="sql-orderby"> - <title id="sql-orderby-title"><literal>ORDER BY</literal> Clause</title> + <refsect2 id="sql-orderby" xreflabel="ORDER BY Clause"> + <title><literal>ORDER BY</literal> Clause</title> <para> The optional <literal>ORDER BY</literal> clause has this general form: @@ -1407,8 +1403,8 @@ SELECT name FROM distributors ORDER BY code; </para> </refsect2> - <refsect2 id="sql-limit"> - <title id="sql-limit-title"><literal>LIMIT</literal> Clause</title> + <refsect2 id="sql-limit" xreflabel="LIMIT Clause"> + <title><literal>LIMIT</literal> Clause</title> <para> The <literal>LIMIT</literal> clause consists of two independent @@ -1492,8 +1488,8 @@ FETCH { FIRST | NEXT } [ <replaceable class="parameter">count</replaceable> ] { </para> </refsect2> - <refsect2 id="sql-for-update-share"> - <title id="sql-for-update-share-title">The Locking Clause</title> + <refsect2 id="sql-for-update-share" xreflabel="The Locking Clause"> + <title>The Locking Clause</title> <para> <literal>FOR UPDATE</literal>, <literal>FOR NO KEY UPDATE</literal>, <literal>FOR SHARE</literal> @@ -2086,7 +2082,7 @@ SELECT distributors.* WHERE distributors.name = 'Westward'; used by <productname>MySQL</productname>. The SQL:2008 standard has introduced the clauses <literal>OFFSET ... FETCH {FIRST|NEXT} ...</literal> for the same functionality, as shown above - in <xref linkend="sql-limit" endterm="sql-limit-title"/>. This + in <xref linkend="sql-limit"/>. This syntax is also used by <productname>IBM DB2</productname>. (Applications written for <productname>Oracle</productname> frequently use a workaround involving the automatically |