两个过滤器与RethinkDB

Question

一个OR条件我有一个结构：

type Talk struct { 
    Id string `gorethink:"id,omitempty"` 
    MatchId string 
    UserIdX string 
    UserIdY string 
    UserNameX string 
    UserNameY string 
    CreatedAt time.Time 
} 

我现在Talk结构是这样的：

{ 
    "CreatedAt": Wed Sep 14 2016 21:36:26 GMT+02:00 , 
    "MatchId": "172d51fa-438b-49a5-bbe5-422377f09336" , 
    "UserIdX": "acc4e0b6-d33b-4755-9c0a-ae5309c2ba75" , 
    "UserIdY": "03f76d8b-ed6a-4c0f-9cde-27b17c9e7cdb" , 
    "UserNameX": "Barbara" , 
    "UserNameY": "Louis" , 
    "id": "ead3f1b0-b242-4c6d-8027-a59572b58649" 
} 

我如何可以检索谈话，用单查询，其中：

（UserIdX == talk.UserIdX和UserIdY == talk.UserIdY）OR（UserIdX == talk.UserIdY和UserI DY == talk.UserIdX）

我真正做到这一点像下面这样：

func (talk *Talk) GetTalkByUsersId() bool { 
    talk1 := new(Talk) 
    talk2 := new(Talk) 

    curs, _ := r.Table("Talks"). 
       Filter(r.Row.Field("UserIdX").Eq(talk.UserIdX)). 
       Filter(r.Row.Field("UserIdY").Eq(talk.UserIdY)). 
       Run(api.Sess) 

    curs2, _ := r.Table("Talks"). 
       Filter(r.Row.Field("UserIdX").Eq(talk.UserIdY)). 
       Filter(r.Row.Field("UserIdY").Eq(talk.UserIdX)). 
       Run(api.Sess) 

    curs.One(&talk1) 
    curs2.One(&talk2) 
    if talk1.Id == "" && talk2.Id == "" { 
     return false 
    } 
    if talk1.Id != "" { 
     talk.copyTalk(talk1) 
    } else { 
     talk.copyTalk(talk2) 
    } 
    return true 
} 

我怎样才能得到这个以更简单的方式工作？

Answer 1

我要在这里召唤@ daniel-cannon，但我认为这就是您要查找的内容，并且将大大简化此查询并将其仅减少为单个查询。但是，只有两个小窍门：

• r.And和r.Or和他们的两个用例都非常你的朋友做一些棘手的逻辑条件。
  • https://www.rethinkdb.com/api/javascript/#and
  • https://www.rethinkdb.com/api/javascript/#or
• 可以提供匿名函数.Filter做的事情，将是一种丑陋的简化r.Row模式。

r.Table("talks").Filter(func(talk r.Term) r.Term { 
    return r.Or(
     r.And(talk.Field("UserIdX").Eq(UserIdX), talk.Field("UserIdX").Eq(UserIdY)), 
     r.And(talk.Field("UserIdY").Eq(UserIdX), talk.Field("UserIdX").Eq(UserIdY)), 
    ) 
}).Run(api.Sess) 

我希望这有助于！