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<title>Registers a User Defined Function for use as a collating function in SQL statements</title>
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<h1 class="refname">PDO::sqliteCreateCollation</h1>
<p class="verinfo">(PHP 5 >= 5.3.11, PHP 7)</p><p class="refpurpose"><span class="refname">PDO::sqliteCreateCollation</span> — <span class="dc-title">
Registers a User Defined Function for use as a collating function in SQL statements
</span></p>
</div>
<div class="refsect1 description" id="refsect1-pdo.sqlitecreatecollation-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span> <span class="type">bool</span> <span class="methodname"><strong>PDO::sqliteCreateCollation</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$name</code></span>
, <span class="methodparam"><span class="type"><a href="language.types.callable.html" class="type callable">callable</a></span> <code class="parameter">$callback</code></span>
)</div>
<div class="warning"><strong class="warning">Warning</strong><p class="simpara">This function is
<em class="emphasis">EXPERIMENTAL</em>. The behaviour of this function, its name, and
surrounding documentation may change without notice in a future release of PHP.
This function should be used at your own risk.
</p></div>
</div>
<div class="refsect1 parameters" id="refsect1-pdo.sqlitecreatecollation-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">name</code></dt>
<dd>
<p class="para">
Name of the SQL collating function to be created or redefined.
</p>
</dd>
<dt>
<code class="parameter">callback</code></dt>
<dd>
<p class="para">
The name of a PHP function or user-defined function to apply as a callback, defining the behavior of the collation. It should accept two strings and return as strcmp() does, i.e. it should return -1, 1, or 0 if the first string sorts before, sorts after, or is equal to the second.
</p>
<p class="para">
This function need to be defined as:
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><span class="replaceable">collation</span></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$string1</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$string2</code></span>
)</div>
</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-pdo.sqlitecreatecollation-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 examples" id="refsect1-pdo.sqlitecreatecollation-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-1113">
<p><strong>Example #1 <span class="function"><strong>PDO::sqliteCreateCollation()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$db </span><span style="color: #007700">= new </span><span style="color: #0000BB">PDO</span><span style="color: #007700">(</span><span style="color: #DD0000">'sqlite::memory:'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">exec</span><span style="color: #007700">(</span><span style="color: #DD0000">"CREATE TABLE test (col1 string)"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">exec</span><span style="color: #007700">(</span><span style="color: #DD0000">"INSERT INTO test VALUES ('a1')"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">exec</span><span style="color: #007700">(</span><span style="color: #DD0000">"INSERT INTO test VALUES ('a10')"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">exec</span><span style="color: #007700">(</span><span style="color: #DD0000">"INSERT INTO test VALUES ('a2')"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">sqliteCreateCollation</span><span style="color: #007700">(</span><span style="color: #DD0000">'NATURAL_CMP'</span><span style="color: #007700">, </span><span style="color: #DD0000">'strnatcmp'</span><span style="color: #007700">);<br />foreach (</span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT col1 FROM test ORDER BY col1"</span><span style="color: #007700">) as </span><span style="color: #0000BB">$row</span><span style="color: #007700">) {<br /> echo </span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #DD0000">'col1'</span><span style="color: #007700">] . </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br />echo </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />foreach (</span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT col1 FROM test ORDER BY col1 COLLATE NATURAL_CMP"</span><span style="color: #007700">) as </span><span style="color: #0000BB">$row</span><span style="color: #007700">) {<br /> echo </span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #DD0000">'col1'</span><span style="color: #007700">] . </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>The above example will output:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
a1
a10
a2
a1
a2
a10
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-pdo.sqlitecreatecollation-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
This method is not available with the SQLite2 driver.
Use the old style sqlite API for that instead.
</p>
</p></blockquote>
</div>
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