一,回顾
上一部分讲述了“在ADO.NET中利用DataTable对象,将其作为参数传给存贮过程”。
通过DataTable实例,完成了两部分的内容:
1)DataTable的数据传输给Stored Procedure
2)利用DataTable的TVP数据,可以参与别的实体数据读写(DataReader)。
这一部分的内容,通过Collection对象,还是要实现上边的两个实例。
二,在ADO.NET中利用Collection对象,将其作为参数传给存贮过程
通过实例,大家对各个特性和参数的如何使用,有更深刻的感性认识。同时,通过
这些实例的改造,也可做出符合自己的程序代码。
这次,还是主要输出Sample,包含两部分的内容:
1)DataTable的数据传输给Stored Procedure
2)利用DataTable的TVP数据,可以参与别的实体数据读写(DataReader)。
具体实例如下:
//---Main Sub
private void btnCollection_Click(object sender, EventArgs e)
{
//------利用OrderItem object
List<OrderItem> orderItems = new List<OrderItem>();
orderItems.Add(new OrderItem() { OrderId = 901, CustomerId = 67, OrderedAt = DateTime.Now });
orderItems.Add(new OrderItem() { OrderId = 902, CustomerId = 68, OrderedAt = DateTime.Now });
OrderItemCollection itemCollection = new OrderItemCollection();
itemCollection.AddRange(orderItems);
//------利用OrderDetail object
List<OrderDetail> orderDetails = new List<OrderDetail>();
orderDetails.Add(new OrderDetail() { OrderId = 901, LineNumber = 1, ProductId = 34, Quantity = 2, Price = 10.5m });
orderDetails.Add(new OrderDetail() { OrderId = 901, LineNumber = 2, ProductId = 100, Quantity = 45, Price = 3.8m });
orderDetails.Add(new OrderDetail() { OrderId = 901, LineNumber = 3, ProductId = 56, Quantity = 67, Price = 9.1m });
orderDetails.Add(new OrderDetail() { OrderId = 902, LineNumber = 1, ProductId = 88, Quantity = 5, Price = 88.5m });
orderDetails.Add(new OrderDetail() { OrderId = 902, LineNumber = 2, ProductId = 1, Quantity = 345, Price = 0.465m });
OrderDetailCollection detailCollection = new OrderDetailCollection();
detailCollection.AddRange(orderDetails);
//----
using (SqlConnection conn = new SqlConnection("Data Source=;Initial Catalog=AdventureWorks;User ID=saassword="))
{
conn.Open();
//---Passing a Table-Valued Parameter to a Stored Pcocedure
using (SqlCommand cmd = new SqlCommand("dbo.OrderItem$Insert", conn))
{
cmd.CommandType = CommandType.StoredProcedure;
//---注意:下边的两个参数名,要和SP的参数名一致。
SqlParameter tvpOrderItem = cmd.Parameters.AddWithValue("@OrderHeaders", itemCollection);
SqlParameter tvpOrderDetail = cmd.Parameters.AddWithValue("@OrderDetails", detailCollection);
tvpOrderItem.SqlDbType = SqlDbType.Structured;
tvpOrderDetail.SqlDbType = SqlDbType.Structured;
cmd.ExecuteNonQuery();
}
//---Streadming rows with a dataReader
string sql = @"select tvp1.OrderId, tvp1.CustomerId, tvp2.LineNumber, tvp2.ProductId
from dbo.OrderItem as tvp1 INNER JOIN @tvpDetail as tvp2 ON tvp1.OrderId=tvp2.OrderId
order by tvp2.OrderId, tvp2.LineNumber;";
SqlCommand readCommand = new SqlCommand(sql, conn);
readCommand.CommandType = CommandType.Text;
SqlParameter tvpDetail = readCommand.Parameters.AddWithValue("@tvpDetail", detailCollection);
tvpDetail.SqlDbType = SqlDbType.Structured;
tvpDetail.TypeName = "dbo.OrderDetail$Udt";
SqlDataReader reader = readCommand.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(string.Format("OrderId={0}, CustomrId={1}, LineNumber={2}, ProductId={3}",
reader.GetInt32(0), reader.GetInt32(1), reader.GetInt32(2), reader.GetInt32(3)));
}
reader.Close();
// Output results:
//------------------
//OrderId=901, CustomrId=67, LineNumber=1, ProductId=34
//OrderId=901, CustomrId=67, LineNumber=2, ProductId=100
//OrderId=901, CustomrId=67, LineNumber=3, ProductId=56
//OrderId=902, CustomrId=68, LineNumber=1, ProductId=88
//OrderId=902, CustomrId=68, LineNumber=2, ProductId=1
//------------------
conn.Close();
}
}
//---OrderItem object
public sealed class OrderItem
{
public int OrderId { get; set; }
public int CustomerId { get; set; }
public DateTime OrderedAt { get; set; }
}
//---OrderDetail object
public sealed class OrderDetail
{
public int OrderId { get; set; }
public int LineNumber { get; set; }
public int ProductId { get; set; }
public int Quantity { get; set; }
public decimal Price { get; set; }
}
//---OrderItemCollection
public sealed class OrderItemCollection: List<OrderItem>, IEnumerable<SqlDataRecord>
{
#region IEnumerable<SqlDataRecord> Members
public new IEnumerator<SqlDataRecord> GetEnumerator()
{
SqlDataRecord record = new SqlDataRecord(
new SqlMetaData("OrderId", SqlDbType.Int),
new SqlMetaData("CustomerId", SqlDbType.Int),
new SqlMetaData("OrderedAt", SqlDbType.DateTime));
foreach(OrderItem item in this.ToArray())
{
record.SetInt32(0, item.OrderId);
record.SetInt32(1, item.CustomerId);
record.SetDateTime(2, item.OrderedAt);
yield return record;
}
}
#endregion
}
//---OrderDetailCollection
public sealed class OrderDetailCollection: List<OrderDetail>, IEnumerable<SqlDataRecord>
{
#region IEnumerable<SqlDataRecord> Members
public new IEnumerator<SqlDataRecord> GetEnumerator()
{
SqlDataRecord record = new SqlDataRecord(
new SqlMetaData("OrderId", SqlDbType.Int),
new SqlMetaData("LineNumber", SqlDbType.Int),
new SqlMetaData("roductId", SqlDbType.Int),
new SqlMetaData("Quantity", SqlDbType.Int),
new SqlMetaData("rice", SqlDbType.Money));
foreach (OrderDetail detail in this.ToArray())
{
record.SetInt32(0, detail.OrderId);
record.SetInt32(1, detail.LineNumber);
record.SetInt32(2, detail.ProductId);
record.SetInt32(3, detail.Quantity);
record.SetDecimal(4, detail.Price);
yield return record;
}
}
#endregion
}
三,其他
通过Table-Values三部分的内容描述和实例,相信大家对TVP的应用有了一定的了解。
在编程中也许有人还是习惯在插入多项或Select多行数据时,使用笨拙的逗号分隔列表或XML,
虽其能够胜任,但不是以习惯的对象方式存在,而且存取速度也很慢。
所以,我建议大家在使用IN语句等需要发送多行数据的编程时,多考虑使用TVP的方式,会取满意的效果。
关于这方面的内容,还需要大家不断的交流和探讨。
四,参考文档
参看URL:
ms-help://MS.SQLCC.v10/MS.SQLSVR.v10.en/s10de_1devconc/html/5e95a382-1e01-4c74-81f5-055612c2ad99.htm
ms-help://MS.MSDNQTR.v90.en/wd_adonet/html/370c16d5-db7b-43e3-945b-ccaab35b739b.htm |
|