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This document uses PHP Chinese website manual Release
(PECL mongo >=1.2.11)
MongoCollection::distinct — 获取集合里指定键的不同值的列表。
$key
[, array $query
] )distinct 命令返回集合里给定键不同值的列表。
key
要使用的键。
query
一个可选的查询参数
返回不同值的数组, 或者在失败时返回 FALSE
Example #1 MongoCollection::distinct() 例子
<?php
$m = new Mongo ;
$db = $m -> selectDB ( "test" );
$db -> dropCollection ( "distinct" );
$c = $db -> distinct ;
$c -> insert (array( "stuff" => "bar" , "zip-code" => 10010 ));
$c -> insert (array( "stuff" => "foo" , "zip-code" => 10010 ));
$c -> insert (array( "stuff" => "bar" , "zip-code" => 99701 ), array( "w" => 1 ));
$retval = $c -> distinct ( "zip-code" );
var_dump ( $retval );
$retval = $c -> distinct ( "zip-code" , array( "stuff" => "foo" ));
var_dump ( $retval );
$retval = $c -> distinct ( "zip-code" , array( "stuff" => "bar" ));
var_dump ( $retval );
?>
以上例程会输出:
array(2) { [0]=> int(10010) [1]=> int(99701) } array(1) { [0]=> int(10010) } array(2) { [0]=> int(10010) [1]=> int(99701) }
Example #2 内嵌文档的 MongoCollection::distinct() 例子
<?php
$c -> insert (array( "user" => array( "points" => 25 )));
$c -> insert (array( "user" => array( "points" => 31 )));
$c -> insert (array( "user" => array( "points" => 25 )));
$retval = $c -> distinct ( "user.points" );
var_dump ( $retval );
$retval = $c -> distinct ( "user.nonexisting" );
var_dump ( $retval );
?>
以上例程会输出:
array(2) { [0]=> int(25) [1]=> int(31) } array(0) { }