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Add an example for counting rows in SELECT statements.

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Probably still need to apply a <blink> tag to this.


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@181049 c90b9560-bf6c-de11-be94-00142212c4b1
This commit is contained in:
Dan Scott 2005-03-01 00:37:59 +00:00
parent 7943785327
commit 98b9b722e8
1 changed files with 81 additions and 7 deletions
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88
reference/pdo/functions/PDOStatement-rowCount.xml
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@ -1,5 +1,5 @@
<?xml version='1.0' encoding='iso-8859-1'?>
<!-- $Revision: 1.4 $ -->
<!-- $Revision: 1.5 $ -->
<!-- Generated by xml_proto.php v2.1. Found in /scripts directory of phpdoc. -->
<refentry id="function.PDOStatement-rowCount">
<refnamediv>
@ -8,8 +8,8 @@
Returns the number of rows affected by the last SQL statement
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>int</type><methodname>PDOStatement::rowCount</methodname>
<void/>
@ -28,8 +28,17 @@
behaviour is not guaranteed for all databases and should not be relied
on for portable applications.
</para>
<example><title>Return the number of deleted rows</title>
<programlisting role="php">
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title>Return the number of deleted rows</title>
<para>
<function>PDOStatement::rowCount</function> returns the number of
rows affected by a DELETE, INSERT, or UPDATE statement.
</para>
<programlisting role="php">
<![CDATA[
<?php
/* Delete all rows from the FRUIT table */
@ -42,8 +51,73 @@ $count = $del->rowCount();
print("Deleted $count rows.\n");
?>
]]>
</programlisting>
</example>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
Deleted 9 rows.
]]>
</screen>
</example>
<example>
<title>Counting rows returned by a SELECT statement</title>
<para>
For most databases, <function>PDOStatement::rowCount</function> does not
return the number of rows affected by a SELECT statement. Instead, use
<function>PDO::query</function> to issue a SELECT COUNT(*) statement
with the same predicates as your intended SELECT statement, then use
<function>PDOStatement::fetchSingle</function> to retrieve the number
of rows that will be returned. Your application can then perform the
correct action.
</para>
<programlisting role="php">
<![CDATA[
<?php
$sql = "SELECT COUNT(*) FROM fruit WHERE calories > 100";
if ($res = $conn->query($sql)) {
// Check the number of rows that match the SELECT statement
if ($res->fetchSingle() > 0) {
// Issue the real SELECT statement and work with the results
$sql = "SELECT name FROM fruit WHERE calories > 100";
foreach ($conn->query($sql) as $row) {
print "Name: " . $row['NAME'] . "\n";
}
}
// No rows matched -- do something else
else {
print "No rows matched the query.";
}
}
$res = null;
$conn = null;
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
apple
banana
orange
pear
]]>
</screen>
</example>
</para>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>PDOStatement::query</function></member>
<member><function>PDOStatement::fetchSingle</function></member>
</simplelist>
</para>
</refsect1>
</refentry>