将数据发送到数据库时出错

Question

我正在尝试传输数据以将它们写入数据库.但我有错误"恐慌:运行时错误:无效的内存地址或无指针取消引用"在这个函数中,我等待来自客户端的数据

func handlePacket(conn net.Conn) {
    rw := bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn))
    defer conn.Close()

    packet := model.RegistrationMessage{}
    client := JsonDecoderMessage(rw).Decode(&packet)
    if client != nil {
        puts("Error from Decode.Please NO :(")
    }

    if packet.MessageType == model.AUTH_MESSAGE {
        puts("Auth")
    } else if packet.MessageType == model.REGS_MESSAGE {
        puts("Regs")
        Registration(packet.Login, packet.Password)
        puts("good")
    }
}

在这里我建立了与数据库的连接,我尝试在数据库中发送数据

var db *sql.DB

func InitDataBase() {
    psqlInfo := fmt.Sprintf("host=%s port=%d user=%s "+
        "password=%s dbname=%s sslmode=disable",
        host, port, user, password, dbname)
    db, err := sql.Open("postgres", psqlInfo)
    if err != nil {
        panic(err)
    }
    defer db.Close()

    err = db.Ping()
    if err != nil {
        panic(err)
    }
    fmt.Println("Successfully connected!")
}
func Registration(email, password string) {
    sqlStatement := `INSERT INTO account0( email,password)
        VALUES ($1, $2) RETURNING id`
    id := 0
    err := db.QueryRow(sqlStatement, email, password).Scan(&id)
    if err != nil {
        panic(err)
    }
}

Answer 1

defer db.Close()将在InitDataBase()返回时执行,因此当您使用db时Registration,会导致错误.

您应该db.Close()在程序退出之前或在完成数据库工作之后调用,以先到者为准.