PHP中的mongodb group操作实例
2014-09-10 08:59
627 查看
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
复制代码 代码如下:> db.fruit.group(
{
key: { category: 1},
cond: { _id: { $gt: 2 } },
reduce: function(obj, prev) {
prev.items.push(obj.name);
prev.count++;
},
initial: { items : [] ,count:0}
}
);
[
{
"category" : "fruit",
"items" : [
"banana"
],
"count" : 1
},
{
"category" : "veggie",
"items" : [
"corn",
"broccoli"
],
"count" : 2
}
]
php代码如下:
复制代码 代码如下:$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
复制代码 代码如下:> 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。
您可能感兴趣的文章:
相关文章推荐
- PHP中的mongodb group操作实例
- PHP操作MongoDB实例
- php操作mongoDB实例分析
- php操作mongoDB实例分析
- PHP操作MongoDB实例
- php7 操作mongodb 封装类 有实例
- MongoDB在PHP中操作实例
- mongodb group php 操作
- PHP操作Mongodb封装类完整实例
- PHP 操作Mongodb 实例
- PHP操作MongoDB实例 --- ttlsa教程系列之mongodb(十一)
- PHP 操作Mongodb 实例
- Java与MongoDB的配合使用备忘3-聚合操作group具体实例
- PHP操作MongoDB
- PHP与MONGODB的结果集操作
- PHP操作MongoDB时的整数问题及对策
- 用PHP实现MONGODB的基本操作
- PHP与MONGODB的UPDATE操作
- MongoDB的group分组操作
- php文件操作实例代码