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<title>Changes the user of the specified database connection</title>
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<h1 class="refname">mysqli::change_user</h1>
<h1 class="refname">mysqli_change_user</h1>
<p class="verinfo">(PHP 5)</p><p class="refpurpose"><span class="refname">mysqli::change_user</span> -- <span class="refname">mysqli_change_user</span> — <span class="dc-title">Changes the user of the specified database connection</span></p>
</div>
<div class="refsect1 description" id="refsect1-mysqli.change-user-description">
<h3 class="title">Description</h3>
<p class="para">Object oriented style</p>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>mysqli::change_user</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$user</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$password</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$database</code></span>
)</div>
<p class="para rdfs-comment">Procedural style</p>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>mysqli_change_user</strong></span>
( <span class="methodparam"><span class="type"><a href="class.mysqli.html" class="type mysqli">mysqli</a></span> <code class="parameter">$link</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$user</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$password</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$database</code></span>
)</div>
<p class="para rdfs-comment">
Changes the user of the specified database connection and sets the current
database.
</p>
<p class="para">
In order to successfully change users a valid <em><code class="parameter">username</code></em> and
<em><code class="parameter">password</code></em> parameters must be provided and that user must have
sufficient permissions to access the desired database. If for any reason authorization
fails, the current user authentication will remain.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-mysqli.change-user-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">
link</code></em></span><dd>
<p class="para">Procedural style only: A link identifier
returned by <span class="function"><a href="function.mysqli-connect.html" class="function">mysqli_connect()</a></span> or <span class="function"><a href="mysqli.init.html" class="function">mysqli_init()</a></span>
</p></dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">user</code></em></span>
<dd>
<p class="para">
The MySQL user name.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">password</code></em></span>
<dd>
<p class="para">
The MySQL password.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">database</code></em></span>
<dd>
<p class="para">
The database to change to.
</p>
<p class="para">
If desired, the <strong><code>NULL</code></strong> value may be passed resulting in only changing
the user and not selecting a database. To select a database in this
case use the <span class="function"><a href="mysqli.select-db.html" class="function">mysqli_select_db()</a></span> function.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-mysqli.change-user-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 notes" id="refsect1-mysqli.change-user-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
Using this command will always cause the current database connection to
behave as if was a completely new database connection, regardless of if
the operation was completed successfully. This reset includes performing
a rollback on any active transactions, closing all temporary tables, and
unlocking all locked tables.
</p>
</p></blockquote>
</div>
<div class="refsect1 examples" id="refsect1-mysqli.change-user-examples">
<h3 class="title">Examples</h3>
<div class="example" id="example-1649">
<p><strong>Example #1 <span class="methodname"><strong>mysqli::change_user()</strong></span> example</strong></p>
<div class="example-contents"><p>Object oriented style</p></div>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br /></span><span style="color: #FF8000">/* connect database test */<br /></span><span style="color: #0000BB">$mysqli </span><span style="color: #007700">= new </span><span style="color: #0000BB">mysqli</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">, </span><span style="color: #DD0000">"test"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* check connection */<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">mysqli_connect_errno</span><span style="color: #007700">()) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect failed: %s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">mysqli_connect_error</span><span style="color: #007700">());<br /> exit();<br />}<br /><br /></span><span style="color: #FF8000">/* Set Variable a */<br /></span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SET @a:=1"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* reset all and select a new database */<br /></span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">change_user</span><span style="color: #007700">(</span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">, </span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br />if (</span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT DATABASE()"</span><span style="color: #007700">)) {<br /> </span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">fetch_row</span><span style="color: #007700">();<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Default database: %s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]);<br /> </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">close</span><span style="color: #007700">();<br />}<br /><br />if (</span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT @a"</span><span style="color: #007700">)) {<br /> </span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">fetch_row</span><span style="color: #007700">();<br /> if (</span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">] === </span><span style="color: #0000BB">NULL</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Value of variable a is NULL\n"</span><span style="color: #007700">);<br /> }<br /> </span><span style="color: #0000BB">$result</span><span style="color: #007700">-></span><span style="color: #0000BB">close</span><span style="color: #007700">();<br />}<br /><br /></span><span style="color: #FF8000">/* close connection */<br /></span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-></span><span style="color: #0000BB">close</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>Procedural style</p></div>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/* connect database test */<br /></span><span style="color: #0000BB">$link </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">, </span><span style="color: #DD0000">"test"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* check connection */<br /></span><span style="color: #007700">if (!</span><span style="color: #0000BB">$link</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect failed: %s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">mysqli_connect_error</span><span style="color: #007700">());<br /> exit();<br />}<br /><br /></span><span style="color: #FF8000">/* Set Variable a */<br /></span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"SET @a:=1"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* reset all and select a new database */<br /></span><span style="color: #0000BB">mysqli_change_user</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">, </span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">, </span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br />if (</span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"SELECT DATABASE()"</span><span style="color: #007700">)) {<br /> </span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_fetch_row</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Default database: %s\n"</span><span style="color: #007700">, </span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]);<br /> </span><span style="color: #0000BB">mysqli_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br />}<br /><br />if (</span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">, </span><span style="color: #DD0000">"SELECT @a"</span><span style="color: #007700">)) {<br /> </span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">mysqli_fetch_row</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /> if (</span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">] === </span><span style="color: #0000BB">NULL</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Value of variable a is NULL\n"</span><span style="color: #007700">);<br /> }<br /> </span><span style="color: #0000BB">mysqli_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/* close connection */<br /></span><span style="color: #0000BB">mysqli_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>The above examples will output:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
Default database: world
Value of variable a is NULL
</pre></div>
</div>
</div>
</div>
<div class="refsect1 seealso" id="refsect1-mysqli.change-user-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.mysqli-connect.html" class="function" rel="rdfs-seeAlso">mysqli_connect()</a> - Alias of mysqli::__construct</span></li>
<li class="member"> <span class="function"><a href="mysqli.select-db.html" class="function" rel="rdfs-seeAlso">mysqli_select_db()</a> - Selects the default database for database queries</span></li>
</ul>
</p>
</div>
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