从mgo中的嵌入式数组中检索元素(golang+MangoDB)

package main

import (
    "fmt"
    "gopkg.in/mgo.v2"
    "gopkg.in/mgo.v2/bson"
)

type User struct {
    ID       bson.ObjectId `bson:"_id,omitempty"`
    Username string        `bson:"username"`
    Email    string        `bson:"email"`
    Tags     []string      `bson:"tags"`
}

func main() {
    session, err := mgo.Dial("mongodb://localhost")
    if err != nil {
        panic(err)
    }
    defer session.Close()

    c := session.DB("mydb").C("users")

    // 创建索引以加快查询速度
    index := mgo.Index{
        Key:        []string{"tags"},
        Background: true,
    }
    err = c.EnsureIndex(index)
    if err != nil {
        panic(err)
    }

    // 查询包含特定元素的文档
    query := bson.M{"tags": "golang"}
    var users []User
    err = c.Find(query).All(&users)
    if err != nil {
        panic(err)
    }

    // 打印查询结果
    for _, user := range users {
        fmt.Println(user)
    }
}