在 C# 中将集合插入 SQL 服务器 Table

Question

尝试将集合插入 SQL Server 2014 中的 table。这是我的代码，它执行时没有错误，但是当我检查我的 table - 没有添加任何内容。我的集合对象 orders 也不为空我在调试时可以看到它有 3 个成员。

 IEnumerable<CompleteOrderDetails> orders;
 JoinDetails(doc, ns, xmlFragment1, out orders);

 string connectionstring = null;
 SqlConnection conn;
 connectionstring = "Data Source = DANNY; Initial Catalog = Alliance; Integrated Security = SSPI";

 using (conn = new SqlConnection(connectionstring))
 {
    string customerInsert = "INSERT INTO AmazonCustomer (AddressLine1, AddressLine2, AddressLine3, City, StateOrRegion, AmazonOrderId, PostalCode, Title, ItemPrice, ShippingPrice, Quantity) " + 
                            "VALUES (@AddressLine1, @AddressLine2, @AddressLine3, @City, @StateOrRegion, @AmazonOrderId, @PostalCode, @Title, @ItemPrice, @ShippingPrice, @Quantity)";

    using (SqlCommand query = new SqlCommand(customerInsert))
    {
        query.Connection = conn;

        foreach (var order in orders)
        {
            query.Parameters.Add("@AmazonOrderId", SqlDbType.NVarChar, 150).Value = order.AmazonOrderId;
            query.Parameters.Add("@Name", SqlDbType.NVarChar, 150).Value = order.Name;
            query.Parameters.Add("@AddressLine1", SqlDbType.NVarChar, 150).Value = order.AddressLine1;
            query.Parameters.Add("@AddressLine2", SqlDbType.NVarChar, 150).Value = order.AddressLine2;
            query.Parameters.Add("@AddressLine3", SqlDbType.NVarChar, 150).Value = order.AddressLine3;
            query.Parameters.Add("@City", SqlDbType.NVarChar, 150).Value = order.City;
            query.Parameters.Add("@StateOrRegion", SqlDbType.NVarChar, 150).Value = order.StateOrRegion;
            query.Parameters.Add("@PostalCode", SqlDbType.NVarChar, 150).Value = order.PostalCode;
            query.Parameters.Add("@Title", SqlDbType.NVarChar, 150).Value = order.Title;
            query.Parameters.Add("@ItemPrice", SqlDbType.NVarChar, 150).Value = order.ItemPrice;
            query.Parameters.Add("@ShippingPrice", SqlDbType.NVarChar, 150).Value = order.ShippingPrice;
            query.Parameters.Add("@Quantity", SqlDbType.NVarChar, 150).Value = order.Quantity;
        }

        conn.Open();
        conn.Close();
    }            
}

来自评论的代码编辑

  private static void ExecuteSqlTransaction(IEnumerable<CompleteOrderDetails> orders)
        {
            string connectionstring = null;
            SqlConnection conn;
            SqlTransaction transaction; 
            connectionstring = "Data Source = DANNY; Initial Catalog = Alliance; Integrated Security = SSPI";
            using (conn = new SqlConnection(connectionstring))
            {
                conn.Open();
                transaction = conn.BeginTransaction("Transaction");
                string customerInsert =
                    "INSERT INTO AmazonCustomer (Name, AddressLine1, AddressLine2, AddressLine3, City, StateOrRegion, AmazonOrderId, PostalCode, Title, ItemPrice, ShippingPrice, Quantity) VALUES (@Name, @AddressLine1, @AddressLine2, @AddressLine3, @City, @StateOrRegion, @AmazonOrderId, @PostalCode, @Title, @ItemPrice, @ShippingPrice, @Quantity)";

                using (SqlCommand query = new SqlCommand(customerInsert))
                {
                    query.Connection = conn;
                    query.Transaction = transaction;
                    query.Parameters.Add("@AmazonOrderId", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@Name", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@AddressLine1", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@AddressLine2", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@AddressLine3", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@City", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@StateOrRegion", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@PostalCode", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@Title", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@ItemPrice", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@ShippingPrice", SqlDbType.NVarChar, 150);
                    query.Parameters.Add("@Quantity", SqlDbType.NVarChar, 150);
                    try
                    {
                        foreach (var order in orders)
                        {
                            query.Parameters["@AmazonOrderId"].Value = order.AmazonOrderId ?? Convert.DBNull;
                            query.Parameters["@Name"].Value = order.Name ?? Convert.DBNull;
                            query.Parameters["@AddressLine1"].Value = order.AddressLine1 ?? Convert.DBNull;
                            query.Parameters["@AddressLine2"].Value = order.AddressLine2 ?? Convert.DBNull;
                            query.Parameters["@AddressLine3"].Value = order.AddressLine3 ?? Convert.DBNull;
                            query.Parameters["@City"].Value = order.City ?? Convert.DBNull;
                            query.Parameters["@StateOrRegion"].Value = order.StateOrRegion ?? Convert.DBNull;
                            query.Parameters["@PostalCode"].Value = order.PostalCode ?? Convert.DBNull;
                            query.Parameters["@Title"].Value = order.Title ?? Convert.DBNull;
                            query.Parameters["@ItemPrice"].Value = order.ItemPrice ?? Convert.DBNull;
                            query.Parameters["@ShippingPrice"].Value = order.ShippingPrice ?? Convert.DBNull;
                            query.Parameters["@Quantity"].Value = order.Quantity ?? Convert.DBNull;
                            query.ExecuteNonQuery();
                            transaction.Commit();
                        }
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine("Commit Exception Type: {0}", ex.GetType());
                        Console.WriteLine("   Message: {0}", ex.Message);

                        try
                        {
                            transaction.Rollback();
                        }
                        catch (Exception ex2)
                        {
                            Console.WriteLine("Rollback Exception Type: {0}", ex2.GetType());
                            Console.WriteLine("   Message: {0}", ex2.Message);
                        }
                    }
                }
            }
        }

Answer 1

您打开和关闭连接，但实际上没有执行任何操作。

此外，将参数的添加移到 foreach 循环之外，只需在循环内设置值。

using (SqlCommand query = new SqlCommand(customerInsert))
{
    query.Connection = conn;
    query.Parameters.Add("@AmazonOrderId", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@Name", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@AddressLine1", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@AddressLine2", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@AddressLine3", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@City", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@StateOrRegion", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@PostalCode", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@Title", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@ItemPrice", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@ShippingPrice", SqlDbType.NVarChar, 150);
    query.Parameters.Add("@Quantity", SqlDbType.NVarChar, 150);

    conn.Open();
    foreach (var order in orders)
    {
        query.Parameters["@AmazonOrderId"].Value = order.AmazonOrderId;
        query.Parameters["@Name"].Value = order.Name;
        query.Parameters["@AddressLine1"].Value = order.AddressLine1;
        query.Parameters["@AddressLine2"].Value = order.AddressLine2;
        query.Parameters["@AddressLine3"].Value = order.AddressLine3;
        query.Parameters["@City"].Value = order.City;
        query.Parameters["@StateOrRegion"].Value = order.StateOrRegion;
        query.Parameters["@PostalCode"].Value = order.PostalCode;
        query.Parameters["@Title"].Value = order.Title;
        query.Parameters["@ItemPrice"].Value = order.ItemPrice;
        query.Parameters["@ShippingPrice"].Value = order.ShippingPrice;
        query.Parameters["@Quantity"].Value = order.Quantity;
        query.ExecuteNonQuery();
    }
    conn.Close();
}

Answer 2

除了缺少 ExecuteNonQuery 调用的明显错误外，您的代码将再次失败，因为您在每个循环中添加了参数。这将导致由已定义的参数引起的异常。

您需要使用

清除参数集合

cmd.Parameters.Clear();

在每个循环开始时或更好地定义循环之前的参数，并在循环内部仅更改值

 using (conn = new SqlConnection(connectionstring))
 {
    string customerInsert = @"INSERT INTO AmazonCustomer 
        (AddressLine1, AddressLine2, AddressLine3, City, 
         StateOrRegion, AmazonOrderId, PostalCode, Title, 
         ItemPrice, ShippingPrice, Quantity) 
         VALUES (@AddressLine1, @AddressLine2, @AddressLine3, @City,
         @StateOrRegion, @AmazonOrderId, @PostalCode, @Title, 
         @ItemPrice, @ShippingPrice, @Quantity)";

    using (SqlCommand query = new SqlCommand(customerInsert))
    {
       query.Connection = conn;
       // Not used ???
       // query.Parameters.Add("@Name", SqlDbType.NVarChar, 150)
       query.Parameters.Add("@AddressLine1", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@AddressLine2", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@AddressLine3", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@City", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@StateOrRegion", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@AmazonOrderId", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@PostalCode", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@Title", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@ItemPrice", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@ShippingPrice", SqlDbType.NVarChar, 150);
       query.Parameters.Add("@Quantity", SqlDbType.NVarChar, 150);

       conn.Open(); 
       using(SqlTransaction tr = conn.BeginTransaction())
       {
           foreach (var order in orders)
           {
                // Not used ???
                // query.Parameters["@Name"].Value = order.Name;
                query.Parameters["@AddressLine1"].Value = order.AddressLine1;
                query.Parameters["@AddressLine2"].Value = order.AddressLine2;
                query.Parameters["@AddressLine3"].Value = order.AddressLine3;
                query.Parameters["@City"].Value = order.City;
                query.Parameters["@StateOrRegion"].Value = order.StateOrRegion;
                query.Parameters["@AmazonOrderId"].Value = order.AmazonOrderId;
                query.Parameters["@PostalCode"].Value = order.PostalCode;
                query.Parameters["@Title"].Value = order.Title;
                query.Parameters["@ItemPrice"].Value = order.ItemPrice;
                query.Parameters["@ShippingPrice"].Value = order.ShippingPrice;
                query.Parameters["@Quantity"].Value = order.Quantity;
                query.ExecuteNonQuery();
           }
           tr.Commit();
        }
    }            
}

请注意，连接可以在循环开始时打开，而不是在每个循环中打开，而 using 语句负责关闭和处理它，并且考虑到插入的性质，我建议还封装所有内容在 SqlTransaction 中，因此您的代码更多 'atomic'。

最后，您的查询中有些地方不正确，集合中有一个参数占位符没有匹配的参数 (@ID) 并且查询中有一个没有占位符的参数 (@name).如果不修复这两个错误，您会遇到其他错误。我已将它们从查询和参数集合中删除

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