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<h1 class="refname">MongoCollection::aggregateCursor</h1>
<p class="verinfo">(PECL mongo >=1.5.0)</p><p class="refpurpose"><span class="refname">MongoCollection::aggregateCursor</span> — <span class="dc-title">Execute an aggregation pipeline command and retrieve results through a cursor</span></p>
</div>
<div class="refsect1 description" id="refsect1-mongocollection.aggregatecursor-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span> <span class="type"><a href="class.mongocommandcursor.html" class="type MongoCommandCursor">MongoCommandCursor</a></span> <span class="methodname"><strong>MongoCollection::aggregateCursor</strong></span>
( <span class="methodparam"><span class="type">array</span> <code class="parameter">$command</code></span>
[, <span class="methodparam"><span class="type">array</span> <code class="parameter">$options</code></span>
] )</div>
<p class="para rdfs-comment">
With this method you can execute Aggregation Framework pipelines and
retrieve the results through a cursor, instead of getting just one document
back as you would with <span class="methodname"><a href="mongocollection.aggregate.html" class="methodname">MongoCollection::aggregate()</a></span>.
This method returns a <a href="class.mongocommandcursor.html" class="classname">MongoCommandCursor</a> object.
This cursor object implements the <a href="class.iterator.html" class="classname">Iterator</a> interface
just like the <a href="class.mongocursor.html" class="classname">MongoCursor</a> objects that are returned
by the <span class="methodname"><a href="mongocollection.find.html" class="methodname">MongoCollection::find()</a></span> method.
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<span class="simpara">
The resulting <a href="class.mongocommandcursor.html" class="classname">MongoCommandCursor</a> will inherit this
collection's read preference.
<span class="methodname"><a href="mongocommandcursor.setreadpreference.html" class="methodname">MongoCommandCursor::setReadPreference()</a></span> may be used
to change the read preference before iterating on the cursor.
</span>
</p></blockquote>
</div>
<div class="refsect1 parameters" id="refsect1-mongocollection.aggregatecursor-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">pipeline</code>
</dt>
<dd>
<p class="para">
The Aggregation Framework pipeline to execute.
</p>
</dd>
<dt>
<code class="parameter">options</code></dt>
<dd>
<p class="para">Options for the aggregation command. Valid options include:</p>
<ul class="itemizedlist">
<li class="listitem">
<p class="para"><em>"allowDiskUse"</em></p>
<p class="para">Allow aggregation stages to write to temporary files</p>
</li>
<li class="listitem">
<p class="para"><em>"cursor"</em></p>
<p class="para">
It is possible to configure how many initial documents the server
should return with the first result set. The default initial batch size
is <em>101</em>. You can change it by adding the
<em>batchSize</em> option:
</p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$collection</span><span style="color: #007700">-></span><span style="color: #0000BB">aggregateCursor</span><span style="color: #007700">( <br /> </span><span style="color: #0000BB">$pipeline</span><span style="color: #007700">,<br /> [ </span><span style="color: #DD0000">"cursor" </span><span style="color: #007700">=> [ </span><span style="color: #DD0000">"batchSize" </span><span style="color: #007700">=> </span><span style="color: #0000BB">4 </span><span style="color: #007700">] ]<br />);</span>
</span>
</code></div>
</div>
<p class="para">
This option only configures the size of the first batch. To configure
the size of future batches, please use the
<span class="methodname"><a href="mongocommandcursor.batchsize.html" class="methodname">MongoCommandCursor::batchSize()</a></span> method on the
returned <a href="class.mongocommandcursor.html" class="classname">MongoCommandCursor</a> object.
</p>
</li>
<li class="listitem">
<p class="para"><em>"explain"</em></p>
<p class="para">
Return information on the processing of the pipeline. This option may
cause the command to return a result document that is unsuitable for
constructing a <a href="class.mongocommandcursor.html" class="classname">MongoCommandCursor</a>. If you need
to use this option, you should consider using
<span class="methodname"><a href="mongocollection.aggregate.html" class="methodname">MongoCollection::aggregate()</a></span>.
</p>
</li>
<li class="listitem"><p class="para"><em>"maxTimeMS"</em></p><p class="para">Specifies a cumulative time limit in milliseconds for processing the operation on the server (does not include idle time). If the operation is not completed by the server within the timeout period, a <a href="class.mongoexecutiontimeoutexception.html" class="classname">MongoExecutionTimeoutException</a> will be thrown.</p></li>
</ul>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-mongocollection.aggregatecursor-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns a <a href="class.mongocommandcursor.html" class="classname">MongoCommandCursor</a> object. Because this
implements the <a href="class.iterator.html" class="classname">Iterator</a> interface you can
iterate over each of the results as returned by the command query. The
<a href="class.mongocommandcursor.html" class="classname">MongoCommandCursor</a> also implements the
<a href="class.mongocursorinterface.html" class="classname">MongoCursorInterface</a> interface which adds the
<span class="methodname"><a href="mongocommandcursor.batchsize.html" class="methodname">MongoCommandCursor::batchSize()</a></span>,
<span class="methodname"><a href="mongocommandcursor.dead.html" class="methodname">MongoCommandCursor::dead()</a></span>,
<span class="methodname"><a href="mongocommandcursor.info.html" class="methodname">MongoCommandCursor::info()</a></span> methods.
</p>
</div>
<div class="refsect1 examples" id="refsect1-mongocollection.aggregatecursor-examples">
<h3 class="title">Examples</h3>
<div class="example" id="example-1567">
<p><strong>Example #1 <span class="function"><strong>MongoCollection::aggregateCursor()</strong></span> example</strong></p>
<div class="example-contents"><p>
Finding all of the distinct values for a key.
</p></div>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$m </span><span style="color: #007700">= new </span><span style="color: #0000BB">MongoClient</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$db </span><span style="color: #007700">= </span><span style="color: #0000BB">$m</span><span style="color: #007700">-></span><span style="color: #0000BB">test</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$people </span><span style="color: #007700">= </span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">people</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">drop</span><span style="color: #007700">();<br /><br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Joe"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">4</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Molly"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">43</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Sally"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">22</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Joe"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">22</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Molly"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">87</span><span style="color: #007700">));<br /><br /></span><span style="color: #0000BB">$ages </span><span style="color: #007700">= </span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">aggregateCursor</span><span style="color: #007700">( [<br /> [ </span><span style="color: #DD0000">'$group' </span><span style="color: #007700">=> [ </span><span style="color: #DD0000">'_id' </span><span style="color: #007700">=> </span><span style="color: #DD0000">'$name'</span><span style="color: #007700">, </span><span style="color: #DD0000">'points' </span><span style="color: #007700">=> [ </span><span style="color: #DD0000">'$sum' </span><span style="color: #007700">=> </span><span style="color: #DD0000">'$points' </span><span style="color: #007700">] ] ],<br /> [ </span><span style="color: #DD0000">'$sort' </span><span style="color: #007700">=> [ </span><span style="color: #DD0000">'points' </span><span style="color: #007700">=> -</span><span style="color: #0000BB">1 </span><span style="color: #007700">] ],<br />] );<br /><br />foreach (</span><span style="color: #0000BB">$ages </span><span style="color: #007700">as </span><span style="color: #0000BB">$person</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"</span><span style="color: #007700">{</span><span style="color: #0000BB">$person</span><span style="color: #007700">[</span><span style="color: #DD0000">'_id'</span><span style="color: #007700">]}</span><span style="color: #DD0000">: </span><span style="color: #007700">{</span><span style="color: #0000BB">$person</span><span style="color: #007700">[</span><span style="color: #DD0000">'points'</span><span style="color: #007700">]}</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />}<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"><br />
Molly: 130<br />
Joe: 26<br />
Sally: 22<br />
</div>
</div>
<div class="example" id="example-1568">
<p><strong>Example #2 <span class="function"><strong>MongoCollection::aggregateCursor()</strong></span>
example with different initial batch size</strong></p>
<div class="example-contents"><p>
Finding all of the distinct values for a key.
</p></div>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$m </span><span style="color: #007700">= new </span><span style="color: #0000BB">MongoClient</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$db </span><span style="color: #007700">= </span><span style="color: #0000BB">$m</span><span style="color: #007700">-></span><span style="color: #0000BB">test</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$people </span><span style="color: #007700">= </span><span style="color: #0000BB">$db</span><span style="color: #007700">-></span><span style="color: #0000BB">people</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">drop</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* Insert some sample data */<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Joe"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">4</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Molly"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">43</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Sally"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">22</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Joe"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">22</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">insert</span><span style="color: #007700">(array(</span><span style="color: #DD0000">"name" </span><span style="color: #007700">=> </span><span style="color: #DD0000">"Molly"</span><span style="color: #007700">, </span><span style="color: #DD0000">"points" </span><span style="color: #007700">=> </span><span style="color: #0000BB">87</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">/* Run the command cursor */<br /></span><span style="color: #0000BB">$ages </span><span style="color: #007700">= </span><span style="color: #0000BB">$people</span><span style="color: #007700">-></span><span style="color: #0000BB">aggregateCursor</span><span style="color: #007700">(<br /> [<br /> [ </span><span style="color: #DD0000">'$group' </span><span style="color: #007700">=> [ </span><span style="color: #DD0000">'_id' </span><span style="color: #007700">=> </span><span style="color: #DD0000">'$name'</span><span style="color: #007700">, </span><span style="color: #DD0000">'points' </span><span style="color: #007700">=> [ </span><span style="color: #DD0000">'$sum' </span><span style="color: #007700">=> </span><span style="color: #DD0000">'$points' </span><span style="color: #007700">] ] ],<br /> [ </span><span style="color: #DD0000">'$sort' </span><span style="color: #007700">=> [ </span><span style="color: #DD0000">'points' </span><span style="color: #007700">=> -</span><span style="color: #0000BB">1 </span><span style="color: #007700">] ],<br /> ],<br /> [ </span><span style="color: #DD0000">"cursor" </span><span style="color: #007700">=> [ </span><span style="color: #DD0000">"batchSize" </span><span style="color: #007700">=> </span><span style="color: #0000BB">4 </span><span style="color: #007700">] ]<br />);<br /><br />foreach (</span><span style="color: #0000BB">$ages </span><span style="color: #007700">as </span><span style="color: #0000BB">$person</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"</span><span style="color: #007700">{</span><span style="color: #0000BB">$person</span><span style="color: #007700">[</span><span style="color: #DD0000">'_id'</span><span style="color: #007700">]}</span><span style="color: #DD0000">: </span><span style="color: #007700">{</span><span style="color: #0000BB">$person</span><span style="color: #007700">[</span><span style="color: #DD0000">'points'</span><span style="color: #007700">]}</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />}<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"><br />
Molly: 130<br />
Joe: 26<br />
Sally: 22<br />
</div>
</div>
</div>
<div class="refsect1 seealso" id="refsect1-mongocollection.aggregatecursor-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><span class="methodname"><a href="mongodb.command.html" class="methodname" rel="rdfs-seeAlso">MongoDB::command()</a> - Execute a database command</span></li>
<li class="member"><a href="class.mongocommandcursor.html" class="classname">MongoCommandCursor</a></li>
<li class="member"><span class="methodname"><a href="mongocommandcursor.batchsize.html" class="methodname" rel="rdfs-seeAlso">MongoCommandCursor::batchSize()</a> - Limits the number of elements returned in one batch</span></li>
<li class="member"><span class="methodname"><a href="mongocollection.aggregate.html" class="methodname" rel="rdfs-seeAlso">MongoCollection::aggregate()</a> - Perform an aggregation using the aggregation framework</span></li>
<li class="member">The MongoDB <a href="https://docs.mongodb.com/manual/core/aggregation-pipeline/" class="link external">» aggregation framework</a></li>
</ul>
</p>
</div>
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