Author: paul
Date: 2008-02-29 20:16:57 +0100 (Fri, 29 Feb 2008)
New Revision: 10075
Log:
r29788@arctic: paul | 2008-02-29 11:52:40 -0600
Misc. clarifications re: UNION.
- INTO OUTFILE saves entire UNION result even though it is allowed only
with final SELECT
- emphasize that ORDER BY is typically used in conjunction with LIMIT
inside parens
- extra columns provide identifying information
Modified:
trunk/it/refman-5.1/sql-syntax.xml
trunk/pt/refman-5.1/sql-syntax.xml
trunk/refman-4.1/sql-syntax.xml
trunk/refman-5.0/sql-syntax.xml
trunk/refman-5.1/sql-syntax.xml
trunk/refman-6.0/sql-syntax.xml
Property changes on: trunk
___________________________________________________________________
Name: svk:merge
- 4767c598-dc10-0410-bea0-d01b485662eb:/mysqldoc-local/mysqldoc/trunk:35828
7d8d2c4e-af1d-0410-ab9f-b038ce55645b:/mysqldoc-local/mysqldoc:29613
b5ec3a16-e900-0410-9ad2-d183a3acac99:/mysqldoc-local/mysqldoc/trunk:14218
bf112a9c-6c03-0410-a055-ad865cd57414:/mysqldoc-local/mysqldoc/trunk:29732
+ 4767c598-dc10-0410-bea0-d01b485662eb:/mysqldoc-local/mysqldoc/trunk:35828
7d8d2c4e-af1d-0410-ab9f-b038ce55645b:/mysqldoc-local/mysqldoc:29613
b5ec3a16-e900-0410-9ad2-d183a3acac99:/mysqldoc-local/mysqldoc/trunk:14218
bf112a9c-6c03-0410-a055-ad865cd57414:/mysqldoc-local/mysqldoc/trunk:29788
Modified: trunk/it/refman-5.1/sql-syntax.xml
===================================================================
--- trunk/it/refman-5.1/sql-syntax.xml 2008-02-29 16:48:18 UTC (rev 10074)
+++ trunk/it/refman-5.1/sql-syntax.xml 2008-02-29 19:16:57 UTC (rev 10075)
Changed blocks: 3, Lines Added: 20, Lines Deleted: 10; 2641 bytes
@@ -11443,7 +11443,8 @@
<listitem>
<para>
Only the last <literal>SELECT</literal> statement can use
- <literal>INTO OUTFILE</literal>.
+ <literal>INTO OUTFILE</literal>. (However, the entire
+ <literal>UNION</literal> result is written to the file.)
</para>
</listitem>
@@ -11537,18 +11538,20 @@
</programlisting>
<para>
- Use of <literal>ORDER BY</literal> for individual
+ However, use of <literal>ORDER BY</literal> for individual
<literal>SELECT</literal> statements implies nothing about the
order in which the rows appear in the final result because
<literal>UNION</literal> by default produces an unordered set
- of rows. If <literal>ORDER BY</literal> appears with
- <literal>LIMIT</literal>, it is used to determine the subset
- of the selected rows to retrieve for the
- <literal>SELECT</literal>, but does not necessarily affect the
- order of those rows in the final <literal>UNION</literal>
- result. If <literal>ORDER BY</literal> appears without
- <literal>LIMIT</literal> in a <literal>SELECT</literal>, it is
- optimized away because it will have no effect anyway.
+ of rows. Therefore, the use of <literal>ORDER BY</literal> in
+ this context is typically in conjunction with
+ <literal>LIMIT</literal>, so that it is used to determine the
+ subset of the selected rows to retrieve for the
+ <literal>SELECT</literal>, even though it does not necessarily
+ affect the order of those rows in the final
+ <literal>UNION</literal> result. If <literal>ORDER
+ BY</literal> appears without <literal>LIMIT</literal> in a
+ <literal>SELECT</literal>, it is optimized away because it
+ will have no effect anyway.
</para>
<para>
@@ -11578,6 +11581,13 @@
(SELECT 2, col2a, col2b, ... FROM t2) ORDER BY sort_col, col1a;
</programlisting>
+ <para>
+ Use of an additional column also enables you to determine
+ which <literal>SELECT</literal> each row comes from. Extra
+ columns can provide other identifying information as well,
+ such as a string that indicates a table name.
+ </para>
+
</section>
</section>
Modified: trunk/pt/refman-5.1/sql-syntax.xml
===================================================================
--- trunk/pt/refman-5.1/sql-syntax.xml 2008-02-29 16:48:18 UTC (rev 10074)
+++ trunk/pt/refman-5.1/sql-syntax.xml 2008-02-29 19:16:57 UTC (rev 10075)
Changed blocks: 3, Lines Added: 20, Lines Deleted: 10; 2641 bytes
@@ -11443,7 +11443,8 @@
<listitem>
<para>
Only the last <literal>SELECT</literal> statement can use
- <literal>INTO OUTFILE</literal>.
+ <literal>INTO OUTFILE</literal>. (However, the entire
+ <literal>UNION</literal> result is written to the file.)
</para>
</listitem>
@@ -11537,18 +11538,20 @@
</programlisting>
<para>
- Use of <literal>ORDER BY</literal> for individual
+ However, use of <literal>ORDER BY</literal> for individual
<literal>SELECT</literal> statements implies nothing about the
order in which the rows appear in the final result because
<literal>UNION</literal> by default produces an unordered set
- of rows. If <literal>ORDER BY</literal> appears with
- <literal>LIMIT</literal>, it is used to determine the subset
- of the selected rows to retrieve for the
- <literal>SELECT</literal>, but does not necessarily affect the
- order of those rows in the final <literal>UNION</literal>
- result. If <literal>ORDER BY</literal> appears without
- <literal>LIMIT</literal> in a <literal>SELECT</literal>, it is
- optimized away because it will have no effect anyway.
+ of rows. Therefore, the use of <literal>ORDER BY</literal> in
+ this context is typically in conjunction with
+ <literal>LIMIT</literal>, so that it is used to determine the
+ subset of the selected rows to retrieve for the
+ <literal>SELECT</literal>, even though it does not necessarily
+ affect the order of those rows in the final
+ <literal>UNION</literal> result. If <literal>ORDER
+ BY</literal> appears without <literal>LIMIT</literal> in a
+ <literal>SELECT</literal>, it is optimized away because it
+ will have no effect anyway.
</para>
<para>
@@ -11578,6 +11581,13 @@
(SELECT 2, col2a, col2b, ... FROM t2) ORDER BY sort_col, col1a;
</programlisting>
+ <para>
+ Use of an additional column also enables you to determine
+ which <literal>SELECT</literal> each row comes from. Extra
+ columns can provide other identifying information as well,
+ such as a string that indicates a table name.
+ </para>
+
</section>
</section>
Modified: trunk/refman-4.1/sql-syntax.xml
===================================================================
--- trunk/refman-4.1/sql-syntax.xml 2008-02-29 16:48:18 UTC (rev 10074)
+++ trunk/refman-4.1/sql-syntax.xml 2008-02-29 19:16:57 UTC (rev 10075)
Changed blocks: 3, Lines Added: 20, Lines Deleted: 10; 2626 bytes
@@ -8229,7 +8229,8 @@
<listitem>
<para>
Only the last <literal>SELECT</literal> statement can use
- <literal>INTO OUTFILE</literal>.
+ <literal>INTO OUTFILE</literal>. (However, the entire
+ <literal>UNION</literal> result is written to the file.)
</para>
</listitem>
@@ -8325,18 +8326,20 @@
</programlisting>
<para>
- Use of <literal>ORDER BY</literal> for individual
+ However, use of <literal>ORDER BY</literal> for individual
<literal>SELECT</literal> statements implies nothing about the
order in which the rows appear in the final result because
<literal>UNION</literal> by default produces an unordered set
- of rows. If <literal>ORDER BY</literal> appears with
- <literal>LIMIT</literal>, it is used to determine the subset
- of the selected rows to retrieve for the
- <literal>SELECT</literal>, but does not necessarily affect the
- order of those rows in the final <literal>UNION</literal>
- result. If <literal>ORDER BY</literal> appears without
- <literal>LIMIT</literal> in a <literal>SELECT</literal>, it is
- optimized away because it will have no effect anyway.
+ of rows. Therefore, the use of <literal>ORDER BY</literal> in
+ this context is typically in conjunction with
+ <literal>LIMIT</literal>, so that it is used to determine the
+ subset of the selected rows to retrieve for the
+ <literal>SELECT</literal>, even though it does not necessarily
+ affect the order of those rows in the final
+ <literal>UNION</literal> result. If <literal>ORDER
+ BY</literal> appears without <literal>LIMIT</literal> in a
+ <literal>SELECT</literal>, it is optimized away because it
+ will have no effect anyway.
</para>
<para>
@@ -8366,6 +8369,13 @@
(SELECT 2, col2a, col2b, ... FROM t2) ORDER BY sort_col, col1a;
</programlisting>
+ <para>
+ Use of an additional column also enables you to determine
+ which <literal>SELECT</literal> each row comes from. Extra
+ columns can provide other identifying information as well,
+ such as a string that indicates a table name.
+ </para>
+
</section>
</section>
Modified: trunk/refman-5.0/sql-syntax.xml
===================================================================
--- trunk/refman-5.0/sql-syntax.xml 2008-02-29 16:48:18 UTC (rev 10074)
+++ trunk/refman-5.0/sql-syntax.xml 2008-02-29 19:16:57 UTC (rev 10075)
Changed blocks: 3, Lines Added: 20, Lines Deleted: 10; 2626 bytes
@@ -9008,7 +9008,8 @@
<listitem>
<para>
Only the last <literal>SELECT</literal> statement can use
- <literal>INTO OUTFILE</literal>.
+ <literal>INTO OUTFILE</literal>. (However, the entire
+ <literal>UNION</literal> result is written to the file.)
</para>
</listitem>
@@ -9102,18 +9103,20 @@
</programlisting>
<para>
- Use of <literal>ORDER BY</literal> for individual
+ However, use of <literal>ORDER BY</literal> for individual
<literal>SELECT</literal> statements implies nothing about the
order in which the rows appear in the final result because
<literal>UNION</literal> by default produces an unordered set
- of rows. If <literal>ORDER BY</literal> appears with
- <literal>LIMIT</literal>, it is used to determine the subset
- of the selected rows to retrieve for the
- <literal>SELECT</literal>, but does not necessarily affect the
- order of those rows in the final <literal>UNION</literal>
- result. If <literal>ORDER BY</literal> appears without
- <literal>LIMIT</literal> in a <literal>SELECT</literal>, it is
- optimized away because it will have no effect anyway.
+ of rows. Therefore, the use of <literal>ORDER BY</literal> in
+ this context is typically in conjunction with
+ <literal>LIMIT</literal>, so that it is used to determine the
+ subset of the selected rows to retrieve for the
+ <literal>SELECT</literal>, even though it does not necessarily
+ affect the order of those rows in the final
+ <literal>UNION</literal> result. If <literal>ORDER
+ BY</literal> appears without <literal>LIMIT</literal> in a
+ <literal>SELECT</literal>, it is optimized away because it
+ will have no effect anyway.
</para>
<para>
@@ -9143,6 +9146,13 @@
(SELECT 2, col2a, col2b, ... FROM t2) ORDER BY sort_col, col1a;
</programlisting>
+ <para>
+ Use of an additional column also enables you to determine
+ which <literal>SELECT</literal> each row comes from. Extra
+ columns can provide other identifying information as well,
+ such as a string that indicates a table name.
+ </para>
+
</section>
</section>
Modified: trunk/refman-5.1/sql-syntax.xml
===================================================================
--- trunk/refman-5.1/sql-syntax.xml 2008-02-29 16:48:18 UTC (rev 10074)
+++ trunk/refman-5.1/sql-syntax.xml 2008-02-29 19:16:57 UTC (rev 10075)
Changed blocks: 3, Lines Added: 20, Lines Deleted: 10; 2632 bytes
@@ -11451,7 +11451,8 @@
<listitem>
<para>
Only the last <literal>SELECT</literal> statement can use
- <literal>INTO OUTFILE</literal>.
+ <literal>INTO OUTFILE</literal>. (However, the entire
+ <literal>UNION</literal> result is written to the file.)
</para>
</listitem>
@@ -11545,18 +11546,20 @@
</programlisting>
<para>
- Use of <literal>ORDER BY</literal> for individual
+ However, use of <literal>ORDER BY</literal> for individual
<literal>SELECT</literal> statements implies nothing about the
order in which the rows appear in the final result because
<literal>UNION</literal> by default produces an unordered set
- of rows. If <literal>ORDER BY</literal> appears with
- <literal>LIMIT</literal>, it is used to determine the subset
- of the selected rows to retrieve for the
- <literal>SELECT</literal>, but does not necessarily affect the
- order of those rows in the final <literal>UNION</literal>
- result. If <literal>ORDER BY</literal> appears without
- <literal>LIMIT</literal> in a <literal>SELECT</literal>, it is
- optimized away because it will have no effect anyway.
+ of rows. Therefore, the use of <literal>ORDER BY</literal> in
+ this context is typically in conjunction with
+ <literal>LIMIT</literal>, so that it is used to determine the
+ subset of the selected rows to retrieve for the
+ <literal>SELECT</literal>, even though it does not necessarily
+ affect the order of those rows in the final
+ <literal>UNION</literal> result. If <literal>ORDER
+ BY</literal> appears without <literal>LIMIT</literal> in a
+ <literal>SELECT</literal>, it is optimized away because it
+ will have no effect anyway.
</para>
<para>
@@ -11586,6 +11589,13 @@
(SELECT 2, col2a, col2b, ... FROM t2) ORDER BY sort_col, col1a;
</programlisting>
+ <para>
+ Use of an additional column also enables you to determine
+ which <literal>SELECT</literal> each row comes from. Extra
+ columns can provide other identifying information as well,
+ such as a string that indicates a table name.
+ </para>
+
</section>
</section>
Modified: trunk/refman-6.0/sql-syntax.xml
===================================================================
--- trunk/refman-6.0/sql-syntax.xml 2008-02-29 16:48:18 UTC (rev 10074)
+++ trunk/refman-6.0/sql-syntax.xml 2008-02-29 19:16:57 UTC (rev 10075)
Changed blocks: 3, Lines Added: 20, Lines Deleted: 10; 2632 bytes
@@ -11890,7 +11890,8 @@
<listitem>
<para>
Only the last <literal>SELECT</literal> statement can use
- <literal>INTO OUTFILE</literal>.
+ <literal>INTO OUTFILE</literal>. (However, the entire
+ <literal>UNION</literal> result is written to the file.)
</para>
</listitem>
@@ -11984,18 +11985,20 @@
</programlisting>
<para>
- Use of <literal>ORDER BY</literal> for individual
+ However, use of <literal>ORDER BY</literal> for individual
<literal>SELECT</literal> statements implies nothing about the
order in which the rows appear in the final result because
<literal>UNION</literal> by default produces an unordered set
- of rows. If <literal>ORDER BY</literal> appears with
- <literal>LIMIT</literal>, it is used to determine the subset
- of the selected rows to retrieve for the
- <literal>SELECT</literal>, but does not necessarily affect the
- order of those rows in the final <literal>UNION</literal>
- result. If <literal>ORDER BY</literal> appears without
- <literal>LIMIT</literal> in a <literal>SELECT</literal>, it is
- optimized away because it will have no effect anyway.
+ of rows. Therefore, the use of <literal>ORDER BY</literal> in
+ this context is typically in conjunction with
+ <literal>LIMIT</literal>, so that it is used to determine the
+ subset of the selected rows to retrieve for the
+ <literal>SELECT</literal>, even though it does not necessarily
+ affect the order of those rows in the final
+ <literal>UNION</literal> result. If <literal>ORDER
+ BY</literal> appears without <literal>LIMIT</literal> in a
+ <literal>SELECT</literal>, it is optimized away because it
+ will have no effect anyway.
</para>
<para>
@@ -12025,6 +12028,13 @@
(SELECT 2, col2a, col2b, ... FROM t2) ORDER BY sort_col, col1a;
</programlisting>
+ <para>
+ Use of an additional column also enables you to determine
+ which <literal>SELECT</literal> each row comes from. Extra
+ columns can provide other identifying information as well,
+ such as a string that indicates a table name.
+ </para>
+
</section>
</section>
| Thread |
|---|
| • svn commit - mysqldoc@docsrva: r10075 - in trunk: . it/refman-5.1 pt/refman-5.1 refman-4.1 refman-5.0 refman-5.1 refman-6.0 | paul | 29 Feb |
