Question

我在rethinkdb中有很多字段和项目的表，我希望得到这个表的所有数据但是在项目的情况下我只想要最后2个记录：查看结果和查询

{
  "adm":  "1" ,
  "chat":  "user_273_1" ,
  "id":  "09ce2adc-9d49-4830-9fb6-fb7159f92d08" ,
  "msg": [
      {
          "date":  "2016-07-20T01:43:06.302Z" ,
          "id":  "4e1d85e0-4e1b-11e6-bb9f-2bb985f41f5d" ,
          "msg":  "sgzsrgz" ,
          "nick":  "SonickSeven" ,
          "user":  "1"
      } ,
      {
          "date":  "2016-07-20T01:43:08.832Z" ,
          "id":  "4f9f9200-4e1b-11e6-bb9f-2bb985f41f5d" ,
          "msg":  "egser" ,
          "nick":  "SonickSeven" ,
          "user":  "1"
      } ,
      {
          "date":  "2016-07-20T01:43:55.233Z" ,
          "id":  "6b47cd10-4e1b-11e6-bb9f-2bb985f41f5d" ,
          "msg":  "sergse" ,
          "nick":  "SonickSeven" ,
          "user":  "1"
      }
  ],
  "optChat": [
      {
      "height": 0 ,
      "minizar": true ,
      "position": false ,
      "user":  "1" ,
      "user2":  "273" ,
      "width": 0 ,
      "x": 0 ,
      "y": 0
      }
  ]
}

并显示：

{
  "adm":  "1" ,
  "chat":  "user_273_1" ,
  "id":  "09ce2adc-9d49-4830-9fb6-fb7159f92d08" ,
  "msg": [
      {
          "date":  "2016-07-20T01:43:08.832Z" ,
          "id":  "4f9f9200-4e1b-11e6-bb9f-2bb985f41f5d" ,
          "msg":  "egser" ,
          "nick":  "SonickSeven" ,
          "user":  "1"
      } ,
      {
          "date":  "2016-07-20T01:43:55.233Z" ,
          "id":  "6b47cd10-4e1b-11e6-bb9f-2bb985f41f5d" ,
          "msg":  "sergse" ,
          "nick":  "SonickSeven" ,
          "user":  "1"
      }
  ],
  "optChat": [
      {
      "height": 0 ,
      "minizar": true ,
      "position": false ,
      "user":  "1" ,
      "user2":  "273" ,
      "width": 0 ,
      "x": 0 ,
      "y": 0
      }
  ]
}

但我想只显示子字段中的最后两项：＆＃34; msg＆＃34;显示一些喜欢它：

{{1}}

我怎么可能，我搜索过这个在互联网上解决它但我什么都不匹配

Answer 1

您可以在查询结尾添加.merge(function(row) { return {msg: row('msg').slice(-2)}; })。

如何限制rethinkdb中的项目

1 个答案: