如何在mgo中构建一个$or查询

huangapple
go评论105阅读模式
英文:

How to construct an $or query in mgo

问题

我正在尝试将这个JS MongoDB查询转换为Go mgo查询：

  1. var foo = "bar";
  2. db.collection.find({"$or": [{uuid: foo}, {name: foo}]});

这是我目前的代码，但它不起作用：

  1. conditions := bson.M{"$or": []bson.M{bson.M{"uuid": name}, bson.M{"name": name}}}

编辑：现在似乎可以工作了。也许我在某个地方打错了字。

英文:

I am trying to convert this JS MongoDB query into Go mgo query:

  1. var foo = "bar";
  2. db.collection.find({"$or": [ {uuid: foo}, {name: foo} ] });

This is what I've got so far, but it doesn't work:

  1. conditions := bson.M{"$or": []bson.M{bson.M{"uuid": name}, bson.M{"name": name}}}

EDIT: It does seem to work now. Maybe I had a typo somewhere.

答案1

得分: 26

这是一个完整的示例，对我来说运行良好（使用Go 1.4和MongoDB 2.6.5）。

  1. package main
  3. import (
  4.     "fmt"
  5.     "log"
  6.     "gopkg.in/mgo.v2"
  7.     "gopkg.in/mgo.v2/bson"
  8. )
  10. type Person struct {
  11.     Num  int
  12.     Uuid string
  13.     Name string
  14. }
  16. func main() {
  18.     // 连接到数据库
  19.     session, err := mgo.Dial("localhost")
  20.     if err != nil {
  21.         panic(err)
  22.     }
  23.     defer session.Close()
  25.     // 如果存在，则删除people集合
  26.     c := session.DB("test").C("people")
  27.     c.DropCollection()
  29.     // 添加一些数据
  30.     err = c.Insert(&Person{1, "UUID1", "Joe"},
  31.         &Person{2, "UUID2", "Jane"},
  32.         &Person{3, "UUID3", "Didier"})
  33.     if err != nil {
  34.         log.Fatal(err)
  35.     }
  37.     result := Person{}
  38.     err = c.Find(bson.M{"$or": []bson.M{bson.M{"uuid": "UUID0"}, bson.M{"name": "Joe"}}}).One(&result)
  39.     if err != nil {
  40.         log.Fatal(err)
  41.     }
  43.     fmt.Println(result)
  44. }

希望对你有帮助！

英文:

Here is a complete example which works fine for me (with Go 1.4, and MongoDB 2.6.5)

  1. package main
  3. import (
  4.     "fmt"
  5.     "log"
  6.     "gopkg.in/mgo.v2"
  7.     "gopkg.in/mgo.v2/bson"
  8. )
  10. type Person struct {
  11.     Num int
  12.     Uuid string
  13.     Name string
  14. }
  16. func main() {
  18.     // Connect to the database
  19.     session, err := mgo.Dial("localhost")
  20.     if err != nil {
  21.             panic(err)
  22.     }
  23.     defer session.Close()
  25.     // Remove people collection if any
  26.     c := session.DB("test").C("people")
  27.     c.DropCollection()
  28.     
  29.     // Add some data        
  30.     err = c.Insert(&Person{ 1, "UUID1", "Joe"},
  31.                    &Person{ 2, "UUID2", "Jane"}, 
  32.                    &Person{ 3, "UUID3", "Didier" })
  33.     if err != nil {
  34.             log.Fatal(err)
  35.     }
  37.     result := Person{}
  38.     err = c.Find( bson.M{ "$or": []bson.M{ bson.M{"uuid":"UUID0"}, bson.M{"name": "Joe"} } } ).One(&result)
  39.     if err != nil {
  40.             log.Fatal(err)
  41.     }
  43.     fmt.Println(result)
  44. }

答案2

得分: 0

  1. package main
  3. import (
  4.     "fmt"
  5.     "gopkg.in/mgo.v2"
  6.     "gopkg.in/mgo.v2/bson"
  7. )
  9. func GetAll() []interface{} {
  10.     // 数据库实例
  11.     session, err := mgo.Dial("localhost")
  12.     c := session.DB("yourDbName").C("YourCollectionName")
  13.     foo := "bar"
  14.     orQuery := []bson.M{}
  15.     uidFindQuery := bson.M{"uuid": foo}
  16.     nameFindQuery := bson.M{"name": foo}
  17.     orQuery = append(orQuery, uidFindQuery, nameFindQuery)
  18.     result := []interface{}{}
  19.     err = c.Find(bson.M{"$or": orQuery}).All(&result)
  20.     fmt.Println("错误", err)
  21.     fmt.Println("您期望的数据", result)
  22.     return result
  23. }

参考链接：
https://gopkg.in/mgo.v2 Go语言中最好的MongoDB接口

英文: 
  1.     package main
  2.     
  3.     import (
  4.      "fmt"
  5.         "gopkg.in/mgo.v2"
  6.         "gopkg.in/mgo.v2/bson"
  7.     
  8.     )
  9. func GetAll()[]interface{}{
  10.            //Data Base Instance
  11.         session, err := mgo.Dial("localhost")
  12.         c := session.DB("yourDbName").C("YourCollectionName")
  13.             foo := "bar"
  14.             orQuery := []bson.M{}
  15.             uidFindQuery := bson.M{uuid: foo}
  16.             nameFindQuery := bson.M{name: foo}
  17.             orQuery = append(orQuery, uidFindQuery, nameFindQuery)
  18.              result := []interface{}{}
  19.             err := c.Find(bson.M{"$or":orQuery}).All(&result);
  20.            fmt.Println("error", err)
  21.            fmt.Println("Your expected Data",result)
  22.            return result
  23.             
  24.    } `

>Reference
https://gopkg.in/mgo.v2 Best Mongo db interface for go lang

huangapple
  • 本文由 发表于 2014年12月6日 03:39:19
  • 转载请务必保留本文链接：https://go.coder-hub.com/27323408.html
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  • mgo
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