php-doc-en/reference/pdo/pdostatement/rowcount.xml

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<refentry xml:id="pdostatement.rowcount" xmlns="http://docbook.org/ns/docbook">
 <refnamediv>
  <refname>PDOStatement::rowCount</refname>
  <refpurpose>
   Returns the number of rows affected by the last SQL statement
  </refpurpose>
 </refnamediv>
 <refsect1 role="description">
  &reftitle.description;
  <methodsynopsis>
   <modifier>public</modifier> <type>int</type><methodname>PDOStatement::rowCount</methodname>
   <void/>
  </methodsynopsis>

  <para>
   <function>PDOStatement::rowCount</function> returns the number of
   rows affected by the last DELETE, INSERT, or UPDATE statement
   executed by the corresponding <literal>PDOStatement</literal> object. 
  </para>
  <para>
   If the last SQL statement executed by the associated 
   <literal>PDOStatement</literal> was a SELECT statement, some databases
   may return the number of rows returned by that statement. However, this
   behaviour is not guaranteed for all databases and should not be relied
   on for portable applications.
  </para>
    <note>
     <para>
      This method returns "0" (zero) with the SQLite driver at all times,
      and with the PostgreSQL driver only when setting the
      <constant>PDO::ATTR_CURSOR</constant> statement attribute to
      <constant>PDO::CURSOR_SCROLL</constant>.
     </para>
  </note>
 </refsect1>
 
  <refsect1 role="returnvalues">
  &reftitle.returnvalues;
  <para>
   Returns the number of rows.
  </para>
 </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 */
$del = $dbh->prepare('DELETE FROM fruit');
$del->execute();

/* Return number of rows that were deleted */
print("Return number of rows that were deleted:\n");
$count = $del->rowCount();
print("Deleted $count rows.\n");
?>
]]>
    </programlisting>
    &example.outputs;
    <screen>
<![CDATA[
Return number of rows that were deleted:
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::fetchColumn</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->fetchColumn() > 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::columnCount</function></member>
    <member><function>PDOStatement::fetchColumn</function></member>
    <member><function>PDO::query</function></member>
   </simplelist>
  </para>

 </refsect1>
</refentry>

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