<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Return an explanation of the query, often useful for optimization and debugging</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="mongocursor.doquery.html">MongoCursor::doQuery</a></div> <div class="next" style="text-align: right; float: right;"><a href="mongocursor.fields.html">MongoCursor::fields</a></div> <div class="up"><a href="class.mongocursor.html">MongoCursor</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="mongocursor.explain" class="refentry"> <div class="refnamediv"> <h1 class="refname">MongoCursor::explain</h1> <p class="verinfo">(PECL mongo >=0.9.2)</p><p class="refpurpose"><span class="refname">MongoCursor::explain</span> — <span class="dc-title">Return an explanation of the query, often useful for optimization and debugging</span></p> </div> <div class="refsect1 description" id="refsect1-mongocursor.explain-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="modifier">public</span> <span class="type">array</span> <span class="methodname"><strong>MongoCursor::explain</strong></span> ( <span class="methodparam">void</span> )</div> </div> <div class="refsect1 parameters" id="refsect1-mongocursor.explain-parameters"> <h3 class="title">Parameters</h3> <p class="para">This function has no parameters.</p> </div> <div class="refsect1 returnvalues" id="refsect1-mongocursor.explain-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns an explanation of the query. </p> </div> <div class="refsect1 examples" id="refsect1-mongocursor.explain-examples"> <h3 class="title">Examples</h3> <div class="example" id="example-1480"> <p><strong>Example #1 <span class="function"><strong>MongoCursor::explain()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /><br />$cursor </span><span style="color: #007700">= </span><span style="color: #0000BB">$collection</span><span style="color: #007700">-></span><span style="color: #0000BB">find</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"x"</span><span style="color: #007700">=></span><span style="color: #0000BB">1</span><span style="color: #007700">), array(</span><span style="color: #DD0000">"y"</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$cursor</span><span style="color: #007700">-></span><span style="color: #0000BB">sort</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"z" </span><span style="color: #007700">=> </span><span style="color: #0000BB">1</span><span style="color: #007700">))-></span><span style="color: #0000BB">limit</span><span style="color: #007700">(</span><span style="color: #0000BB">4</span><span style="color: #007700">)-></span><span style="color: #0000BB">skip</span><span style="color: #007700">(</span><span style="color: #0000BB">5</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$cursor</span><span style="color: #007700">-></span><span style="color: #0000BB">explain</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 something similar to:</p></div> <div class="example-contents screen"> <div class="cdata"><pre> array(8) { ["cursor"]=> string(15) "BtreeCursor x_1" ["startKey"]=> array(1) { ["x"]=> int(1) } ["endKey"]=> array(1) { ["x"]=> int(1) } ["nscanned"]=> float(4) ["n"]=> int(4) ["scanAndOrder"]=> int(1) ["millis"]=> int(3) ["allPlans"]=> array(2) { [0]=> array(3) { ["cursor"]=> string(15) "BtreeCursor x_1" ["startKey"]=> array(1) { ["x"]=> int(1) } ["endKey"]=> array(1) { ["x"]=> int(1) } } [1]=> array(3) { ["cursor"]=> string(11) "BasicCursor" ["startKey"]=> array(0) { } ["endKey"]=> array(0) { } } } } </pre></div> </div> </div> </div> <div class="refsect1 errors" id="refsect1-mongocursor.explain-errors"> <h3 class="title">Errors/Exceptions</h3> <p class="para"> Throws <a href="class.mongoconnectionexception.html" class="classname">MongoConnectionException</a> if it cannot reach the database. </p> </div> <div class="refsect1 seealso" id="refsect1-mongocursor.explain-seealso"> <h3 class="title">See Also</h3> <p class="para"> MongoDB core docs on <a href="http://docs.mongodb.org/manual/reference/method/cursor.explain/" class="link external">» explain</a>. </p> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; 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