package main import ( "database/sql" "fmt" mqtt "github.com/eclipse/paho.mqtt.golang" _ "github.com/go-sql-driver/mysql" "github.com/google/uuid" "go_mqtt/models" _ "go_mqtt/models" "go_mqtt/mydb" _ "go_mqtt/mydb" "log" "strings" "time" ) func getMySqlDB() (*sql.DB, error){ dsn := "root:Skyinno251,@tcp(47.242.184.139:3306)/appserver?charset=utf8mb4&parseTime=True&loc=Local" db, err := sql.Open("mysql", dsn) if err != nil { log.Fatal(err) return nil,err } db.SetConnMaxLifetime(time.Minute * 5) // 连接最大生命周期 db.SetMaxOpenConns(50) // 最大连接数 db.SetMaxIdleConns(10) // 最大空闲连接数 //defer mydb.Close() err = db.Ping() // 检查连接是否成功建立。如果失败,则返回错误。 if err != nil { // 处理连接失败的情况。例如,打印错误信息并退出程序。 log.Println("47.242.184.139:3306连接失败") fmt.Println("Connection failed:", err) return nil,err } else { log.Println("47.242.184.139:3306连接成功") fmt.Println("Connected successfully") //复制代码到你的Go文件中,并根据你的实际情况修改DSN中的用户名、密码、主机名、端口和数据库名。 //然后运行你的程序。如果一切正常,你应该能够看到查询结果被打印出来。 //如果遇到任何问题,检查你的DSN是否正确,以及MySQL服务器是否正在运行并允许连接。 //确保你的防火墙设置允许你的应用程序访问MySQL端口(默认是3306)。 //如果你使用的是远程数据库,确保网络设置允许你从当前位置访问数据库服务器。 return db,nil } } func moreDBConnect() { db1, err := mydb.NewDatabase("appserver", "root", "Skyinno251,", "47.242.184.139", 3306) if err != nil { fmt.Println("Error connecting to db1:", err) return } defer db1.Db.Close() fmt.Println("Connected to databases:", db1.Name) //db2, err := mydb.NewDatabase("db2", "user2", "password2", "localhost", 3306) //if err != nil { // fmt.Println("Error connecting to db2:", err) // return //} //defer db2.Conn.Close() // //fmt.Println("Connected to databases:", db1.Name, "and", db2.Name) } func queryOneDataByMySql(db *sql.DB) { //DB.QueryRow 用于查询单行数据,返回的是一个单独的 Row 对象。和 Query 不同,它只返回一行结果,适合用于查询根据条件唯一的数据: var temperature models.Temperature err := db.QueryRow("SELECT id,create_date,data_date,data_hour,data_minute,humidity,location_desc,temperature,topic FROM temperature order by id desc limit 0,?",1).Scan(&temperature.Id, &temperature.CreateDate, &temperature.DataDate, &temperature.DataHour, &temperature.DataMinute, &temperature.Humidity, &temperature.LocationDesc, &temperature.Temperature, &temperature.Topic) if err != nil { fmt.Println("QueryRow failed:", err) return } fmt.Printf("Temperature Id:%d\n", temperature.Id) fmt.Printf("Temperature: %+v\n", temperature) } func queryMoreDataByMySql(db *sql.DB) { //DB.QueryRow 用于查询单行数据,返回的是一个单独的 Row 对象。和 Query 不同,它只返回一行结果,适合用于查询根据条件唯一的数据: rows, err := db.Query("SELECT id,create_date,data_date,data_hour,data_minute,humidity,location_desc,temperature,topic FROM temperature WHERE id > ? and id < ?", 0,30) if err != nil { fmt.Println("Query failed:", err) return } defer rows.Close() // 确保在使用完毕后关闭资源 items := make([]models.Temperature, 0) for rows.Next() { var temperature models.Temperature if err := rows.Scan(&temperature.Id, &temperature.CreateDate, &temperature.DataDate, &temperature.DataHour, &temperature.DataMinute, &temperature.Humidity, &temperature.LocationDesc, &temperature.Temperature, &temperature.Topic); err != nil { fmt.Println("Scan failed:", err) return } items = append(items, temperature) fmt.Println(items) } } //插入单条数据 func insertDataByMySql(db *sql.DB,temperature *models.Temperature) { //插入操作: stmt, err := db.Prepare("INSERT INTO temperature(create_date,data_date,data_hour,data_minute,humidity,location_desc,temperature,topic) VALUES(?, ?,?, ?,?, ?,?, ?)") if err != nil { fmt.Println("Prepare failed:", err) return } res, err := stmt.Exec(&temperature.CreateDate, &temperature.DataDate, &temperature.DataHour, &temperature.DataMinute, &temperature.Humidity, &temperature.LocationDesc, &temperature.Temperature, &temperature.Topic) if err != nil { fmt.Println("Exec failed:", err) return } lastID, _ := res.LastInsertId() fmt.Printf("Inserted Temperature with ID: %d\n", lastID) } //事务处理:保证数据一致性 func insertMoreDataByMySql(db *sql.DB,temperature *models.Temperature) { tx, err := db.Begin() if err != nil { fmt.Println("Begin transaction failed:", err) return } _, err = tx.Exec("UPDATE users SET age = ? WHERE id = ?", 35, 1) if err != nil { tx.Rollback() // 如果发生错误,回滚事务 fmt.Println("Exec failed:", err) return } err = tx.Commit() // 提交事务 if err != nil { fmt.Println("Commit failed:", err) return } fmt.Println("Transaction committed successfully") } func dbTest() { // 初始化数据库连接 DB, err := sql.Open("mysql", "root:123456@tcp(127.0.0.1:3306)/test") if err != nil { fmt.Println("Error opening DB:", err) return } defer DB.Close() DB.SetConnMaxLifetime(time.Minute * 5) DB.SetMaxOpenConns(50) DB.SetMaxIdleConns(10) // 测试数据库连接 if err := DB.Ping(); err != nil { fmt.Println("Connection failed:", err) return } fmt.Println("Connected successfully") // 查询数据 rows, _ := DB.Query("SELECT id, name FROM users") defer rows.Close() for rows.Next() { var id int var name string rows.Scan(&id, &name) fmt.Printf("ID: %d, Name: %s\n", id, name) } // 插入数据 stmt, _ := DB.Prepare("INSERT INTO users(name, age) VALUES(?, ?)") stmt.Exec("Jane Doe", 28) // 删除数据 stmt, _ = DB.Prepare("DELETE FROM users WHERE id = ?") stmt.Exec(1) } func timing(client mqtt.Client) { //定时器,10秒钟执行一次 ticker := time.NewTicker(5 * time.Second) for { time := <-ticker.C fmt.Println("定时器====>", time.String()) if !client.IsConnectionOpen() { client.Connect() } else { fmt.Println("client has connect") //moreDBConnect() db, err := getMySqlDB() if err == nil { queryOneDataByMySql(db) //mydb.Close() } } } } var messagePubHandler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) { fmt.Printf("Received message: %s from topic: %s\n", msg.Payload(), msg.Topic()) message := fmt.Sprintf("%s",msg.Payload()) topic := fmt.Sprintf("%s",msg.Topic()) fmt.Println(message) result := strings.Split(message, " ") fmt.Println(result[0]) fmt.Println(result[1]) now := time.Now() temperature := new(models.Temperature) temperature.CreateDate=now temperature.DataDate=now.Format("2006-01-02") temperature.DataHour=now.Format("2006-01-02 15") temperature.DataMinute=now.Format("2006-01-02 15:04") temperature.Humidity=result[0] temperature.Temperature=result[1] temperature.Topic=topic if topic=="WifiSHT/7C87CE9CA4E6/SHT20" { temperature.LocationDesc="广东省珠海市高新区唐家湾镇东岸村水风三街28号501" } if topic=="WifiSHT/7C87CE9F5CBF/SHT20" { temperature.LocationDesc="广东省珠海市金湾区三灶镇百川路1号1栋1单元1508房" } if topic=="WifiSHT/4CEBD686B6AA/SHT20" { temperature.LocationDesc="广西壮族自治区崇左市天等县天等镇荣华村弄在屯113号" } db, err := getMySqlDB() if err == nil { insertDataByMySql(db,temperature) //mydb.Close() } } var connectHandler mqtt.OnConnectHandler = func(client mqtt.Client) { fmt.Println("Connected") } var connectLostHandler mqtt.ConnectionLostHandler = func(client mqtt.Client, err error) { fmt.Printf("Connect lost: %v", err) } func sub(client mqtt.Client) { topic := "gomqtt01" token := client.Subscribe(topic, 1, nil) token.Wait() fmt.Printf("Subscribed to topic: %s", topic) } func subTemperature(client mqtt.Client) { topic := "WifiSHT/+/SHT20" token := client.Subscribe(topic, 1, nil) token.Wait() fmt.Printf("Subscribed to topic: %s", topic) } func publish(client mqtt.Client) { num := 999999000000000000 for i := 0; i < num; i++ { text := fmt.Sprintf("Message %d", i) token := client.Publish("gomqtt01", 0, false, text) token.Wait() fmt.Println(i) time.Sleep(6 * time.Second) } } func main() { uuid := uuid.New() fmt.Println("Generated UUID:", uuid) var broker = "47.242.184.139" var port = 1883 opts := mqtt.NewClientOptions() opts.AddBroker(fmt.Sprintf("tcp://%s:%d", broker, port)) opts.SetClientID(uuid.String()) opts.SetUsername("admin") opts.SetPassword("publish452131wW452131wW$") opts.SetDefaultPublishHandler(messagePubHandler) opts.OnConnect = connectHandler opts.OnConnectionLost = connectLostHandler client := mqtt.NewClient(opts) if token := client.Connect(); token.Wait() && token.Error() != nil { fmt.Println(token.Error()) } //client.IsConnectionOpen() go timing(client) //sub(client) subTemperature(client) publish(client) //client.Disconnect(1000) }