MongoDB 应用开发
查询
联结查询
示例:
db.getCollection("user").aggregate([
{
$lookup: {
from: "organization",
localField: "orgId",
foreignField: "_id",
as: "organization",
},
},
{
$unwind: {
path: "$organization",
preserveNullAndEmptyArrays: true,
},
},
{
$match: {
"level":"A",
"organization.type": "COM",
},
},
]);