Question

我正在为我的项目开发购物车，我在如何检索orderid和插入另一个表方面遇到了麻烦。

我在sql server中有两个表

Order
orderid (PK) | date| orderstatus| name| shippingaddress| contactnumber| totalprice| customerid|

Order_book
orderid (PK) | ISBN (PK)| quantity

我想从订单表中检索orderid并将其插入order_book，每当订单提交到数据库时，订单表中的orderid是一个增量为1的标识int。

使用c＃从一个表到另一个表同时检索和插入的最佳选项是什么？

感谢。

码::

protected void checkout_Click(object sender, EventArgs e)
{
    SQLInjection sql = new SQLInjection();
    String name;
    String address; 
    int contactnumber;
    if (newaddresspanel.Visible == true)
    {
       name = sql.SafeSqlLiteral(NameLabel.Text, 2);
       address = Address1.Text + " " + Address2.Text + "," + PostalCode.Text + "," + State.SelectedItem.Value;
       contactnumber =  int.Parse(Telephone1.SelectedItem.Value) + int.Parse(Telephone2.Text);
       insertDetails(name, address, contactnumber);
    }
    else if (defaultaddresspanel.Visible)
    {
        SqlConnection myConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["BookWormDBConnectionString"].ConnectionString);//connect to database
        SqlCommand bindDetails = new SqlCommand("SELECT NAME, ADDRESS, TELEPHONE_NUMBER FROM CUSTOMER WHERE CUSTOMERID = @username", myConnection);

        bindDetails.Parameters.Add("@username", SqlDbType.VarChar);
        bindDetails.Parameters["@username"].Value = username;

        try
        {
            myConnection.Open();
            SqlDataReader reader = bindDetails.ExecuteReader();
            while (reader.Read())
            {
                name = reader["NAME"].ToString();
                address = reader["ADDRESS"].ToString();
                contactnumber = int.Parse(reader["TELEPHONE_NUMBER"].ToString());
                insertDetails(name, address, contactnumber);

                }
            reader.Dispose();
            myConnection.Close();
        }
        catch (SqlException se)
        {


        }
    }
    try
    {
        cart = (DataTable)HttpContext.Current.Session["Cart"];
        foreach (DataRow dr in cart.Rows)
        {
            int isbn = int.Parse(dr["ISBN"].ToString());
            int quantity = int.Parse(dr["quantity"].ToString());
            insertOrderbook(isbn, quantity);
        }


    }

    catch (Exception ae)
    {

        Response.Write(ae.Message);

    }

插入订单簿：“哪个失败了”

protected void insertOrderbook(int isbn, int quantity)
{

    int orderid;
    SqlConnection myConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["BookWormDBConnectionString"].ConnectionString);//connect to database
    SqlCommand orderId = new SqlCommand("SELECT SCOPE_IDENTITY() FROM ORDERBOOK", myConnection);


    try
    {
        myConnection.Open();

        orderid = int.Parse(orderId.ExecuteScalar().ToString());
            SqlCommand insertOrderBook = new SqlCommand("INSERT INTO ORDERBOOK_BOOK (ISBN, ORDERID, QUANTITY) VALUES (@isbn, @orderid, @quantity)", myConnection);

            insertOrderBook.Parameters.Add("@isbn", SqlDbType.Int);
            insertOrderBook.Parameters["@isbn"].Value = isbn;

            insertOrderBook.Parameters.Add("@orderid", SqlDbType.Int);
            insertOrderBook.Parameters["@orderid"].Value = orderid;

            insertOrderBook.Parameters.Add("@quantity", SqlDbType.Int);
            insertOrderBook.Parameters["@quantity"].Value = quantity;

            insertOrderBook.ExecuteNonQuery();
            myConnection.Close();
        }
    catch (SqlException se)
    {
        Response.Write(se.Message);
    }
}

插入订单详情::

protected void insertDetails(string name, string address, int contactnumber)
{
    SqlConnection myConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["BookWormDBConnectionString"].ConnectionString);//connect to database
    SqlCommand orderDetails = new SqlCommand("INSERT INTO ORDERBOOK (DATE, ORDERSTATUS, TOTALPRICE, SHIPPING_ADD, CUSTOMERID, NAME, CONTACTNUMBER) VALUES (@date, @orderstatus, @totalprice, @shippingadd, @username, @name, @contactnumber)", myConnection);
    orderDetails.Parameters.Add("@date", SqlDbType.DateTime);
    orderDetails.Parameters["@date"].Value = getTime();

    orderDetails.Parameters.Add("@orderstatus", SqlDbType.VarChar);
    orderDetails.Parameters["@orderstatus"].Value = "Order Processing";

    orderDetails.Parameters.Add("@totalprice", SqlDbType.Decimal);
    orderDetails.Parameters["@totalprice"].Value = totalPrice;

    orderDetails.Parameters.Add("@shippingadd", SqlDbType.VarChar);
    orderDetails.Parameters["@shippingadd"].Value = address;

    orderDetails.Parameters.Add("@name", SqlDbType.VarChar);
    orderDetails.Parameters["@name"].Value = name;

    orderDetails.Parameters.Add("@contactnumber", SqlDbType.Int);
    orderDetails.Parameters["@contactnumber"].Value = contactnumber;

    orderDetails.Parameters.Add("@username", SqlDbType.VarChar);
    orderDetails.Parameters["@username"].Value = username;

    try {
        myConnection.Open();
        orderDetails.ExecuteNonQuery();
        myConnection.Close();

    }
    catch ( SqlException se)
    {


    }
}

错误：输入字符串格式不正确

我尝试调试它，不知何故，orderid显示为0

Answer 1

如果我理解正确，您希望在插入订单时检索新创建的orderId，然后将该ID放在order_book中。

要检索上次创建的值，请在将订单表中的项目插入后立即使用SELECT SCOPE_IDENTITY()。这将为您提供orderId以插入order_book。

Answer 2

你正在做这个选择

SELECT SCOPE_IDENTITY() FROM ORDERBOOK

你应该做的是在你的订单簿插入SP中添加一个输出参数（例如@orderBookId），然后在插入之后，你应该这样做

SELECT @orderBookId = SCOPE_IDENTITY()

注意没有FROM子句，并确保在C＃代码上添加参数作为输出参数。

然后，在插入细节时，只需添加@orderBookId作为输入参数即可。

同时从一个表中检索并插入值到另一个表

2 个答案: