Question

我如何使用mongo golang驱动程序将以下查询转换为管道

var result = _context.Messages
            .Where(x => x.timestamp != null)
            .GroupBy(x => x.timestamp.Value.Year.ToString()+"-" + x.timestamp.Value.Month.ToString())
            .Select(x => new { date = x.Key, count = x.Count() })

Answer 1

要在go lang MongoDB驱动程序中运行 $ facet ，请使用以下代码，只需替换您的连接字符串和数据库名称

package main

import (
    "context"
    "time"
    "fmt"
    "go.mongodb.org/mongo-driver/bson"
    "go.mongodb.org/mongo-driver/mongo"
    "go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
    ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
    client, err := mongo.Connect(ctx, options.Client().ApplyURI("mongodb_connect_string"))
    if err != nil {
        panic(err)
    }
    defer client.Disconnect(ctx)

    database := client.Database("testdb")
    transFront := database.Collection("transFront")



    query1 := bson.A{bson.D{{"$match", bson.D{{"appName", "app-38"}}}}, bson.D{{"$count", "count"}}}
    query2 := bson.A{bson.D{{"$match", bson.D{{"appName", "app-43"}}}}, bson.D{{"$count", "count"}}}
    query3 := bson.A{bson.D{{"$match", bson.D{{"appName", "app--1"}}}}, bson.D{{"$count", "count"}}}

    facetStage := bson.D{{"$facet", bson.D{{"query1", query1}, {"query2", query2}, {"query3", query3}}}}

    showInfoCursor, err := transFront.Aggregate(ctx, mongo.Pipeline{facetStage})
    if err != nil {
            panic(err)
    }
    var showsWithInfo []bson.M
    if err = showInfoCursor.All(ctx, &showsWithInfo); err != nil {
            panic(err)
    }

    fmt.Println(showsWithInfo)
}

如何在Mongo Golang驱动程序中使用聚合$ facet查询

1 个答案: