ReactiveMongo Aggregation 聚合查询模型 -- MyEdu service ticket query

Aggregation 源代码



1)  Get all records

       ticketDB.find(Json.obj("school_bucket" -> "1"))
         .cursor[TicketView].collect[List]().map((tickets: List[TicketView]) => Ok(Json.toJson(tickets)))

2)  Get distinct field
    val distinct = RawCommand(
        BSONDocument("distinct" -> "tickets", "key" -> "school_number", "query" -> BSONDocument("school_bucket" -> "1")))

      // for distinct, but only return one distinct field
      for {
        result1 <- db.command(distinct)
      } yield {
        Ok(toJSON(result1))
      }

3) Get first record for each school

  // return all fields of the first document for each group
      val groupBy = Aggregate("tickets",
        Seq(
          GroupField("school_number")
            (
              "id" -> First("id"),
              "ticket_number" -> First("ticket_number"),
              "school_number" -> First("school_number"),
              "school_bucket" -> First("school_bucket"),
              "school_name" -> First("school_name")
            ),
          Sort(List(Ascending("id"))),
          Match(BSONDocument("school_bucket" -> "1"))
        )
      )

      db.command(groupBy).map(
        s => {
          val result = s.toList.map(doc => toJSON(doc))
          Ok(Json.toJson(result))
        }
      )