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SGML improvements to the DML chapter.

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Neil Conway 2005-03-01 23:45:00 +00:00
parent a2ad04f4b0
commit 87aafa1600
1 changed files with 14 additions and 10 deletions
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doc/src/sgml/dml.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/dml.sgml,v 1.10 2005/01/22 22:56:35 momjian Exp $ --> <!-- $PostgreSQL: pgsql/doc/src/sgml/dml.sgml,v 1.11 2005/03/01 23:45:00 neilc Exp $ -->
<chapter id="dml"> <chapter id="dml">
<title>Data Manipulation</title> <title>Data Manipulation</title>
@ -38,10 +38,10 @@
</para> </para>
<para> <para>
To create a new row, use the <literal>INSERT</literal> command. To create a new row, use the <xref linkend="sql-insert"
The command requires the table name and a value for each of the xreflabel="sql-insert-title"> command. The command requires the
columns of the table. For example, consider the products table table name and a value for each of the columns of the table. For
from <xref linkend="ddl">: example, consider the products table from <xref linkend="ddl">:
<programlisting> <programlisting>
CREATE TABLE products ( CREATE TABLE products (
product_no integer, product_no integer,
@ -98,7 +98,9 @@ INSERT INTO products DEFAULT VALUES;
To do <quote>bulk loads</quote>, that is, inserting a lot of data, To do <quote>bulk loads</quote>, that is, inserting a lot of data,
take a look at the <xref linkend="sql-copy" take a look at the <xref linkend="sql-copy"
endterm="sql-copy-title"> command. It is not as flexible as the endterm="sql-copy-title"> command. It is not as flexible as the
<command>INSERT</command> command, but is more efficient. <command>INSERT</command> command, but is more efficient. Refer to
<xref linkend="populate"> for more information on improving bulk
loading performance.
</para> </para>
</tip> </tip>
</sect1> </sect1>
@ -188,7 +190,7 @@ UPDATE products SET price = price * 1.10;
<para> <para>
You can update more than one column in an You can update more than one column in an
<literal>UPDATE</literal> command by listing more than one <command>UPDATE</command> command by listing more than one
assignment in the <literal>SET</literal> clause. For example: assignment in the <literal>SET</literal> clause. For example:
<programlisting> <programlisting>
UPDATE mytable SET a = 5, b = 3, c = 1 WHERE a &gt; 0; UPDATE mytable SET a = 5, b = 3, c = 1 WHERE a &gt; 0;
@ -222,9 +224,11 @@ UPDATE mytable SET a = 5, b = 3, c = 1 WHERE a &gt; 0;
</para> </para>
<para> <para>
You use the <literal>DELETE</literal> command to remove rows; the You use the <xref linkend="sql-delete"
syntax is very similar to the <literal>UPDATE</literal> command. xreflabel="sql-delete-title"> command to remove rows; the syntax is
For instance, to remove all rows from the products table that have a price of 10, use very similar to the <command>UPDATE</command> command. For
instance, to remove all rows from the products table that have a
price of 10, use
<programlisting> <programlisting>
DELETE FROM products WHERE price = 10; DELETE FROM products WHERE price = 10;
</programlisting> </programlisting>