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<chapter id="dml">

<title>Data Manipulation</title>

</para>

<para>

To create a new row, use the <literal>INSERT</literal> command.

The command requires the table name and a value for each of the

columns of the table. For example, consider theproductstable

from <xref linkend="ddl">:

To create a new row, use the <xref linkend="sql-insert"

xreflabel="sql-insert-title"> command. The command requires the

table name and a value for each of thecolumns of thetable. For

example, consider the products tablefrom <xref linkend="ddl">:

<programlisting>

CREATE TABLE products (

product_no integer,

To do <quote>bulk loads</quote>, that is, inserting a lot of data,

take a look at the <xref linkend="sql-copy"

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>

</tip>

</sect1>

<para>

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:

<programlisting>

UPDATE mytable SET a = 5, b = 3, c = 1 WHERE a &gt; 0;

</para>

<para>

You use the <literal>DELETE</literal> command to remove rows; the

syntax is very similar to the <literal>UPDATE</literal> command.

For instance, to remove all rows from the products table that have a price of 10, use

You use the <xref linkend="sql-delete"

xreflabel="sql-delete-title"> command to remove rows; the syntax is

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>

DELETE FROM products WHERE price = 10;

</programlisting>