一、回顧

　　上一部分講述了“在ADO.NET中利用DataTable對象，將其作為參數(shù)傳給存貯過程”。

通過DataTable實(shí)例，完成了兩部分的內(nèi)容：

1）DataTable的數(shù)據(jù)傳輸給Stored Procedure

2）利用DataTable的TVP數(shù)據(jù)，可以參與別的實(shí)體數(shù)據(jù)讀寫(DataReader)。

這一部分的內(nèi)容，通過Collection對象，還是要實(shí)現(xiàn)上邊的兩個實(shí)例。

二、在ADO.NET中利用Collection對象，將其作為參數(shù)傳給存貯過程

　　通過實(shí)例，大家對各個特性和參數(shù)的如何使用，有更深刻的感性認(rèn)識。同時，通過 這些實(shí)例的改造，也可做出符合自己的程序代碼。

這次，還是主要輸出Sample，包含兩部分的內(nèi)容：

1）DataTable的數(shù)據(jù)傳輸給Stored Procedure

2）利用DataTable的TVP數(shù)據(jù)，可以參與別的實(shí)體數(shù)據(jù)讀寫(DataReader)。

具體實(shí)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=sa;Password="))

{

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：下邊的兩個參數(shù)名，要和SP的參數(shù)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&gt; 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(&quot;ProductId", SqlDbType.Int),

new SqlMetaData("Quantity&quot;, SqlDbType.Int),

new SqlMetaData("Price", 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

　　通過Table-Values三部分的內(nèi)容描述和實(shí)例，相信大家對TVP的應(yīng)用有了一定的了解。 在編程中也許有人還是習(xí)慣在插入多項(xiàng)或Select多行數(shù)據(jù)時，使用笨拙的逗號分隔列表或XML， 雖其能夠勝任，但不是以習(xí)慣的對象方式存在，而且存取速度也很慢。 所以，我建議大家在使用IN語句等需要發(fā)送多行數(shù)據(jù)的編程時，多考慮使用TVP的方式，會取滿意的效果。 關(guān)于這方面的內(nèi)容，還需要大家不斷的交流和探討。