在MongoDB-3.2.7中通过一个查询从两个集合中获取所需的文档

db.collection1.aggregate([
  {
    $lookup: {
      from: "collection2",
      localField: "field1",
      foreignField: "field2",
      as: "result"
    }
  }
])

db.collection1.aggregate([
  {
    $lookup: {
      from: "collection2",
      localField: "field1",
      foreignField: "field2",
      as: "result"
    }
  },
  {
    $match: {
      // 进行条件过滤
    }
  },
  {
    $project: {
      // 选择需要的字段
    }
  },
  {
    $sort: {
      // 进行排序
    }
  }
])