使用golang从MongoDB批量获取记录

package main

import (
    "context"
    "fmt"
    "log"
    "time"

    "go.mongodb.org/mongo-driver/bson"
    "go.mongodb.org/mongo-driver/mongo"
    "go.mongodb.org/mongo-driver/mongo/options"
)

type Person struct {
    Name  string
    Age   int
    Email string
}

func main() {
    // 设置MongoDB连接选项
    clientOptions := options.Client().ApplyURI("mongodb://localhost:27017")

    // 连接到MongoDB
    client, err := mongo.Connect(context.TODO(), clientOptions)
    if err != nil {
        log.Fatal(err)
    }

    // 检查连接
    err = client.Ping(context.TODO(), nil)
    if err != nil {
        log.Fatal(err)
    }

    fmt.Println("Connected to MongoDB!")

    // 获取要查询的集合
    collection := client.Database("mydb").Collection("people")

    // 创建一个切片来存储查询结果
    var results []Person

    // 设置查询条件
    filter := bson.D{{}}

    // 执行查询
    cur, err := collection.Find(context.TODO(), filter)
    if err != nil {
        log.Fatal(err)
    }

    // 遍历查询结果
    for cur.Next(context.TODO()) {
        var elem Person
        err := cur.Decode(&elem)
        if err != nil {
            log.Fatal(err)
        }
        results = append(results, elem)
    }

    // 检查游标错误
    if err := cur.Err(); err != nil {
        log.Fatal(err)
    }

    // 关闭游标
    cur.Close(context.TODO())

    fmt.Printf("Found %d documents\n", len(results))
    for _, result := range results {
        fmt.Println(result)
    }

    // 断开与MongoDB的连接
    err = client.Disconnect(context.TODO())
    if err != nil {
        log.Fatal(err)
    }
    fmt.Println("Connection to MongoDB closed.")
}