mongodb group php 操作
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2022-04-14 07:56:17
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紧接着上篇来,这篇主要讲,mongodb的group功能,做的还是挺强大的,相当对于find(),skip(),distinct()等,用法比较复杂。 测试数据 db.fruit.find();{ "_id" : 1, "category" : "fruit", "name" : "apple" }{ "_id" : 2, "category" : "fruit", "name" :
紧接着上篇来,这篇主要讲,mongodb的group功能,做的还是挺强大的,相当对于find(),skip(),distinct()等,用法比较复杂。
测试数据
> db.fruit.find(); { "_id" : 1, "category" : "fruit", "name" : "apple" } { "_id" : 2, "category" : "fruit", "name" : "peach" } { "_id" : 3, "category" : "fruit", "name" : "banana" } { "_id" : 4, "category" : "veggie", "name" : "corn" } { "_id" : 5, "category" : "veggie", "name" : "broccoli" }
1,根据category分组
> db.fruit.group( ?????? { ???????? key: { category: 1}, ???????? reduce: function(obj, prev) { ???????????????????? prev.items.push(obj.name); ???????????????? }, ???????? initial: { items : [] } ?????? } ??? ); [ ??????? { ??????????????? "category" : "fruit", ??????????????? "items" : [ ??????????????????????? "apple", ??????????????????????? "peach", ??????????????????????? "banana" ??????????????? ] ??????? }, ??????? { ??????????????? "category" : "veggie", ??????????????? "items" : [ ??????????????????????? "corn", ??????????????????????? "broccoli" ??????????????? ] ??????? } ]
php代码如下
$keys = array("category" => 1); $initial = array("items" => array()); $reduce = "function (obj, prev) { prev.items.push(obj.name); }"; $g = $collection->group($keys, $initial, $reduce); print_r($g);?? //结果如下。 Array ( ??? [retval] => Array ??????? ( ??????????? [0] => Array ??????????????? ( ??????????????????? [category] => fruit ??????????????????? [items] => Array ??????????????????????? ( ??????????????????????????? [0] => apple ??????????????????????????? [1] => peach ??????????????????????????? [2] => banana ??????????????????????? ) ??????????????? ) ??????????? [1] => Array ??????????????? ( ??????????????????? [category] => veggie ??????????????????? [items] => Array ??????????????????????? ( ??????????????????????????? [0] => corn ??????????????????????????? [1] => broccoli ??????????????????????? ) ??????????????? ) ??????? ) ??? [count] => 5 ??? [keys] => 2 ??? [ok] => 1 )
2,根据category来分组,并统计count
> db.fruit.group( ?????????? { ???????????? key: { category: 1}, ???????????? cond: { _id: { $gt: 2 } }, ???????????? reduce: function(obj, prev) { ??????????????? prev.items.push(obj.name); ?? ??? ??? ??? ?prev.count++; ???????????? }, ???????????? initial: { items : [] ,count:0} ?????????? } ??????? ); [ ?? ?{ ?? ??? ?"category" : "fruit", ?? ??? ?"items" : [ ?? ??? ??? ?"banana" ?? ??? ?], ?? ??? ?"count" : 1 ?? ?}, ?? ?{ ?? ??? ?"category" : "veggie", ?? ??? ?"items" : [ ?? ??? ??? ?"corn", ?? ??? ??? ?"broccoli" ?? ??? ?], ?? ??? ?"count" : 2 ?? ?} ]
php代码如下:
$keys = array("category" => 1); $initial = array("items" => array(),'count'=>0); $reduce = "function (obj, prev) { " . ?? ??? ??? ?? "prev.items.push(obj.name); " . ?? ??? ??? ?? "prev.count++;" . ?? ??? ?? "}"; $condition = array('condition' => array("_id" => array( '$gt' => 2))); $g = $collection->group($keys, $initial, $reduce, $condition); print_r($g);?? //结果如下。 Array ( ??? [retval] => Array ??????? ( ??????????? [0] => Array ??????????????? ( ??????????????????? [category] => fruit ??????????????????? [items] => Array ??????????????????????? ( ??????????????????????????? [0] => banana ??????????????????????? ) ??????????????????? [count] => 1 ??????????????? ) ??????????? [1] => Array ??????????????? ( ??????????????????? [category] => veggie ??????????????????? [items] => Array ??????????????????????? ( ??????????????????????????? [0] => corn ??????????????????????????? [1] => broccoli ??????????????????????? ) ??????????????????? [count] => 2 ??????????????? ) ??????? ) ??? [count] => 3 ??? [keys] => 2 ??? [ok] => 1 )
3,利用aggregate group功能,也挺强大
> db.fruit.aggregate([ ???????????????????? { $match: { _id: {$gt:0} } }, ???????????????????? { $group: { _id: "$category", count: { $sum: 1 } } }, ???????????????????? { $sort: { count: -1 } } ?????????????????? ]); { "_id" : "fruit", "count" : 3 } { "_id" : "veggie", "count" : 2 }
php代码如下:
$cond = array( ??? array( ??????? '$match' => array('_id' => array('$gt' => 0)), ??? ), ??? array( ??????? '$group' => array( ??????????? '_id' => '$category', ?????????? 'count' => array('$sum' => 1), ??????? ), ??? ), ??? array( ??????? '$sort' => array("count" => -1), ??? ), ); $result = $collection->aggregate($cond); print_r($result); //结果如下: Array ( ??? [result] => Array ??????? ( ??????????? [0] => Array ??????????????? ( ??????????????????? [_id] => fruit ??????????????????? [count] => 3 ??????????????? ) ??????????? [1] => Array ??????????????? ( ??????????????????? [_id] => veggie ??????????????????? [count] => 2 ??????????????? ) ??????? ) ??? [ok] => 1 )
mongodb 的select 操作有很多,在这里,只是说了一些常用的功能。
原文地址:mongodb group php 操作, 感谢原作者分享。
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