可以使用mongodb的高级查询$lookup
{
$lookup:
{
from: <collection to join>,
localField: <field from the input documents>,
foreignField: <field from the documents of the "from" collection>,
as: <output array field>
}
}
其实换成相当于sql语句的join用法
SELECT *, <output array field>
FROM collection
WHERE <output array field> IN (SELECT *
FROM <collection to join>
WHERE <foreignField> = <collection.localField>);
我们以php为例,来编写一个$lookup的聚合查询连表多表示例代码:
<?php
$manager = new MongoDB\Driver\Manager("mongodb://localhost:27017");
// 插入数据
$bulk = new MongoDB\Driver\BulkWrite;
// 插入商品数据
$bulk->insert(['prodid' => 1, 'title' => '产品1']);
$bulk->insert(['siteid' => 2, 'title' => '产品2']);
$_data = $manager->executeBulkWrite('test.product', $bulk);
$bulk = new MongoDB\Driver\BulkWrite;
// 插入订单数据
$bulk->insert(['orderid' => 1, 'title' => '订单1',"prodid"=>1]);
$bulk->insert(['orderid' => 2, 'title' => '订单2',"prodid"=>1]);
$_data = $manager->executeBulkWrite('test.order', $bulk);
$param = [
'aggregate' => 'product', //表名
'pipeline' => [
[ '$lookup' => ['from' => "order", 'localField' => 'prodid', 'foreignField' => 'orderid', 'as' => 'orders']
]],
'cursor' => new \stdClass()// 高版本需要带上这个值
];
$command = new \MongoDB\Driver\Command($param);
$cursor = $manager->executeCommand('test', $command);
foreach ($cursor as $document) {
$document = objectToArray($document);
var_dump($document);
}
function objectToArray($object) {
$result = array();
$object = is_object($object) ? get_object_vars($object) : $object;
foreach ($object as $key => $val) {
$val = (is_object($val) || is_array($val)) ? objectToArray($val) : $val;
$result[$key] = $val;
}
return $result;
}
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