php-doc-en/reference/mongo/mongocollection/find.xml
2011-12-29 15:47:06 +00:00

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<?xml version="1.0" encoding="utf-8"?>
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<refentry xml:id="mongocollection.find" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
<refnamediv>
<refname>MongoCollection::find</refname>
<refpurpose>Querys this collection, returning a <class>MongoCursor</class>
for the result set</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<modifier>public</modifier> <type>MongoCursor</type><methodname>MongoCollection::find</methodname>
<methodparam choice="opt"><type>array</type><parameter>query</parameter><initializer>array()</initializer></methodparam>
<methodparam choice="opt"><type>array</type><parameter>fields</parameter><initializer>array()</initializer></methodparam>
</methodsynopsis>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term>
<parameter>query</parameter>
</term>
<listitem>
<para>
The fields for which to search. MongoDB's query language is quite
extensive. The PHP driver will in almost all cases pass the query
straight through to the server, so reading the MongoDB core docs on
<link xlink:href="&url.mongodb.dochub.find;">find</link> is a good idea.
</para>
<warning>
<para>
Please make sure that for all special query operaters (starting with
<literal>$</literal>) you use single quotes so that PHP doesn't try to
replace <literal>"$exists"</literal> with the value of the variable
<literal>$exists</literal>.
</para>
</warning>
</listitem>
</varlistentry>
<varlistentry>
<term>
<parameter>fields</parameter>
</term>
<listitem>
<para>
Fields of the results to return. The array is in the format
<literal>array('fieldname' => true, 'fieldname2' => true)</literal>.
The <literal>_id</literal> field is always returned.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
Returns a cursor for the search results.
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<example>
<title><function>MongoCollection::find</function> example</title>
<para>This example demonstrates how to search for a range.</para>
<programlisting role="php">
<![CDATA[
<?php
$m = new Mongo();
$db = $m->selectDB('test');
$collection = new MongoCollection($db, 'phpmanual');
// search for documents where 5 < x < 20
$rangeQuery = array('x' => array( '$gt' => 5, '$lt' => 20 ));
$cursor = $collection->find($rangeQuery);
foreach ($cursor as $doc) {
var_dump($doc);
}
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
array(2) {
["_id"]=>
object(MongoId)#10 (1) {
["$id"]=>
string(24) "4ebc3e3710b89f2349000000"
}
["x"]=>
int(12)
}
array(2) {
["_id"]=>
object(MongoId)#11 (1) {
["$id"]=>
string(24) "4ebc3e3710b89f2349000001"
}
["x"]=>
int(12)
}
]]>
</screen>
<para>
See <classname>MongoCursor</classname> for more information how to work with cursors.
</para>
</example>
<example>
<title><function>MongoCollection::find</function> example using $where</title>
<para>This example demonstrates how to search a collection using javascript code to reduce the resultset.</para>
<programlisting role="php">
<![CDATA[
<?php
$m = new Mongo();
$db = $m->selectDB('test');
$collection = new MongoCollection($db, 'phpmanual');
$js = "function() {
return this.name == 'Joe' || this.age == 50;
}";
$cursor = $collection->find(array('$where' => $js));
foreach ($cursor as $doc) {
var_dump($doc);
}
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
array(3) {
["_id"]=>
object(MongoId)#7 (1) {
["$id"]=>
string(24) "4ebc3e3710b89f2349000002"
}
["name"]=>
string(3) "Joe"
["age"]=>
int(20)
}
]]>
</screen>
</example>
<example>
<title><function>MongoCollection::find</function> example using $in</title>
<para>This example demonstrates how to search a collection using the $in operator.</para>
<programlisting role="php">
<![CDATA[
<?php
$m = new Mongo();
$db = $m->selectDB('test');
$collection = new MongoCollection($db, 'phpmanual');
$cursor = $collection->find(array(
'name' => array('$in' => array('Joe', 'Wendy'))
));
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
array(3) {
["_id"]=>
object(MongoId)#7 (1) {
["$id"]=>
string(24) "4ebc3e3710b89f2349000002"
}
["name"]=>
string(3) "Joe"
["age"]=>
int(20)
}
]]>
</screen>
</example>
<example>
<title>Getting results as an array</title>
<para>
This returns a <classname>MongoCursor</classname>. Often, when people are
starting out, they are more comfortable using an array. To turn a cursor
into an array, use the <function>iterator_to_array</function> function.
</para>
<programlisting role="php">
<![CDATA[
<?php
$m = new Mongo();
$db = $m->selectDB('test');
$collection = new MongoCollection($db, 'phpmanual');
$cursor = $collection->find();
$array = iterator_to_array($cursor);
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
array(3) {
["4ebc40af10b89f5149000000"]=>
array(2) {
["_id"]=>
object(MongoId)#6 (1) {
["$id"]=>
string(24) "4ebc40af10b89f5149000000"
}
["x"]=>
int(12)
}
["4ebc40af10b89f5149000001"]=>
array(2) {
["_id"]=>
object(MongoId)#11 (1) {
["$id"]=>
string(24) "4ebc40af10b89f5149000001"
}
["x"]=>
int(12)
}
["4ebc40af10b89f5149000002"]=>
array(3) {
["_id"]=>
object(MongoId)#12 (1) {
["$id"]=>
string(24) "4ebc40af10b89f5149000002"
}
["name"]=>
string(3) "Joe"
["age"]=>
int(20)
}
}
]]>
</screen>
<para>
Using <function>iterator_to_array</function> forces the driver to load all of
the results into memory, so do not do this for result sets that are larger
than memory!
</para>
<para>
Also, certain system collections do not have an <literal>_id</literal>
field. If you are dealing with a collection that might have documents
without <literal>_id</literal>s, pass &false; as the second argument to
<function>iterator_to_array</function> (so that it will not try to use the
non-existent <literal>_id</literal> values as keys).
</para>
</example>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<simplelist>
<member><function>MongoCollection::findOne</function></member>
<member><function>MongoCollection::insert</function></member>
<member>MongoDB core docs on <link xlink:href="&url.mongodb.dochub.find;">find</link>.</member>
</simplelist>
</refsect1>
</refentry>
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