我有一個(gè)調(diào)用 sql 連接的 api。這是到某個(gè)遠(yuǎn)程服務(wù)器的 sql 連接。執(zhí)行查詢時(shí)出現(xiàn)錯(cuò)誤“dial tcp xxx:xxx:xxx:xxx:3306: connect: connection refused”sql連接代碼func ConnectToMysqlDB(dbUser, dbPassword, dbHost, dbName string) *sql.DB {    connstr := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s", dbUser, dbPassword, dbHost, "3306", dbName)    var err error    log.Println("Carrying mysql query", connstr)    dB, err := sql.Open("mysql", connstr)    if err != nil {        log.Fatalf("error connection to mysql [%v] ..!!", err)    }    log.Print("mysql initialized ..!!")    return dB}查詢功能func GetUserIDs(dB *sql.DB, users []string) []int {    var newUsers []int    var newUser int    query := "SELECT id FROM phplist_user_user WHERE foreignkey in (%s)"    var usersStr string    for _, val := range users {        usersStr = usersStr + "'" + val + "'" + ","    }    usersStr = strings.TrimSuffix(usersStr, ",")    query = fmt.Sprintf(query, usersStr)    rows, err := dB.Query(query)    if err != nil {        fmt.Printf("Error in query : [%v]", err)    }    defer rows.Close()    for rows.Next() {        rows.Scan(&newUser)        newUsers = append(newUsers, newUser)    }    return newUsers}我收到錯(cuò)誤的原因是什么：查詢錯(cuò)誤：[dial tcp xxx.xxx.xxx.xxx:3306: connect: connection refused]