php-doc-en/reference/mysqli/functions/mysqli-query.xml

<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.9 $ -->
  <refentry id="function.mysqli-query">
   <refnamediv>
    <refname>mysqli_query</refname>
    <refname>mysqli->query</refname>
    <refpurpose>Performs a query on the database</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
    <para>Procedural style:</para>
    <methodsynopsis>
     <type>mixed</type><methodname>mysqli_query</methodname>
     <methodparam><type>mysqli</type><parameter>link</parameter></methodparam>
     <methodparam><type>string</type><parameter>query</parameter></methodparam>
     <methodparam choice='opt'><type>int</type><parameter>resultmode</parameter></methodparam>
    </methodsynopsis>
    <para>Object oriented style (method):</para>
    <classsynopsis>
     <ooclass><classname>mysqli</classname></ooclass>
     <methodsynopsis>
      <type>mixed</type><methodname>query</methodname>
      <methodparam><type>string</type><parameter>query</parameter></methodparam>
      <methodparam choice='opt'><type>int</type><parameter>resultmode</parameter></methodparam>
     </methodsynopsis>
    </classsynopsis>
    <para>
     The <function>mysqli_query</function> function is used to simplify the
     act of performing a query against the database represented by the
     <parameter>link</parameter> parameter. 
    </para>
    <para>
     Functionally, using this
     function is identical to calling <function>mysqli_real_query</function>
     followed either by <function>mysqli_use_result</function> or 
     <function>mysqli_store_result</function> where <parameter>query</parameter>
     is the query string itself and <parameter>resultmode</parameter> is
     either the constant <literal>MYSQLI_USE_RESULT</literal> or 
     <literal>MYSQLI_STORE_RESULT</literal> depending
     on the desired behavior. By default, if the 
     <parameter>resultmode</parameter> is not provided 
     <literal>MYSQLI_STORE_RESULT</literal> is used.     
    </para>
    <para>
     If you execute <function>mysqli_query</function> with <parameter>resultmode</parameter>
     <literal>MYSQLI_USE_RESULT</literal> all subsequent calls will return error 
     <literal>Commands out of sync</literal> unless you call <function>mysqli_free_result</function>.
    </para>
   </refsect1>
   <refsect1>
    &reftitle.returnvalues;
    <para>
     &return.success; For <literal>SELECT, SHOW, DESCRIBE</literal> or
     <literal>EXPLAIN</literal> <function>mysqli_query</function> will return
     a result object.
    </para>
   </refsect1>
   <refsect1>
    &reftitle.seealso;
    <para>
     <function>mysqli_real_query</function>,
     <function>mysqli_multi_query</function>&listendand;
     <function>mysqli_free_result</function>.
    </para>
   </refsect1>
   <refsect1>
    &reftitle.examples;
    <example>
     <title>Object oriented style</title>
     <programlisting role="php">
<![CDATA[
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

/* Create table doesn't return a resultset */
if ($mysqli->query("CREATE TEMPORARY TABLE myCity LIKE City") === TRUE) {
    printf("Table myCity successfully created.\n");
}

/* Select queries return a resultset */
if ($result = $mysqli->query("SELECT Name FROM City LIMIT 10")) {
    printf("Select returned %d rows.\n", $result->num_rows);

    /* free result set */
    $result->close();
}

/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
if ($result = $mysqli->query("SELECT * FROM City", MYSQLI_USE_RESULT)) {

    /* Note, that we can't execute any functions which interact with the
       server until result set was closed. All calls will return an 
       'out of sync' error */
    if (!$mysqli->query("SET @a:='this will not work'")) {
        printf("Error: %s\n", $mysqli->error);
    }
    $result->close();
}

$mysqli->close();
?>
]]>
    </programlisting>
    </example>
    <example>
     <title>Procedural style</title>
     <programlisting role="php">
<![CDATA[
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

/* Create table doesn't return a resultset */
if (mysqli_query($link, "CREATE TEMPORARY TABLE myCity LIKE City") === TRUE) {
    printf("Table myCity successfully created.\n");
}

/* Select queries return a resultset */
if ($result = mysqli_query($link, "SELECT Name FROM City LIMIT 10")) {
    printf("Select returned %d rows.\n", mysqli_num_rows($result));

    /* free result set */
    mysqli_free_result($result);
}

/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
if ($result = mysqli_query($link, "SELECT * FROM City", MYSQLI_USE_RESULT)) {

    /* Note, that we can't execute any functions which interact with the
       server until result set was closed. All calls will return an 
       'out of sync' error */
    if (!mysqli_query($link, "SET @a:='this will not work'")) {
        printf("Error: %s\n", mysqli_error($link));
    }
    mysqli_free_result($result);
}

mysqli_close($link);
?>
]]>
     </programlisting>
    </example>
    &example.outputs;
    <screen>
<![CDATA[
Table myCity successfully created.
Select returned 10 rows.
Error: Commands out of sync;  You can't run this command now
]]>
    </screen>
   </refsect1>
  </refentry>

<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"../../../../manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->