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<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
command.CommandText = &quot;INSERT INTO Orders (CustomerId, OrderDate, &quot; +</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
&quot;ShipAddress, ShipCity, ShipCountry) &quot; + </span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
&quot;VALUES(@CustomerId, @OrderDate, @ShipAddress, @ShipCity, &quot; + &quot;@ShipCountry)
&quot;;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
command.Parameters.Add(&quot;@CustomerId&quot;, order.CustomerId);</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
command.Parameters.Add(&quot;@OrderDate&quot;, order.OrderDate);</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
command.Parameters.Add(&quot;@ShipAddress&quot;, order.ShipAddress);</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
command.Parameters.Add(&quot;@ShipCity&quot;, order.ShipCity);</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
command.Parameters.Add(&quot;@ShipCountry&quot;, order.ShipCountry);</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
connection.Open();</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;</span></p>

<p class=2 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
command.ExecuteNonQuery();</span></p>

<p class=MsoNormal><span style='font-family:宋体'>因为</span><span lang=ES>OrderId</span><span
style='font-family:宋体'>被定义为数据库中自动递增的值，而且把</span><span lang=ES>Order Details</span><span
style='font-family:宋体'>写入数据库时需要这<span style='letter-spacing:.1pt'>个</span></span><span
lang=ES style='letter-spacing:.1pt'>id</span><span style='font-family:宋体;
letter-spacing:.1pt'>，所以</span><span lang=ES style='letter-spacing:.1pt'>OrderId</span><span
style='font-family:宋体;letter-spacing:.1pt'>使用</span><span lang=ES
style='letter-spacing:.1pt'>@@IDENTITY</span><span style='font-family:宋体;
letter-spacing:.1pt'>读取。接着调用方法</span><span lang=ES style='letter-spacing:.1pt'>SetOrderId()</span><span
style='font-family:宋体;letter-spacing:.1pt'>把它设置为</span><span lang=ES
style='letter-spacing:.1pt'>Order</span><span style='font-family:宋体;letter-spacing:
.1pt'>对</span><span style='font-family:宋体'>象：</span></p>

<p class=2 style='margin-top:8.15pt;margin-right:0cm;FTEL:0cm;
margin-left:21.45pt;FTEL:.0001pt;FTEL:18.45pt'><span lang=ES>&nbsp;
command.CommandText = &quot;SELECT @@IDENTITY AS 'Identity' &quot;;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
object identity = command.ExecuteScalar();</span></p>

<p class=2 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
order.SetOrderId(Convert.ToInt32(identity));</span></p>

<p class=MsoNormal><span style='font-family:宋体'>在订单写入数据库后，订单上的所有订单行都使用</span><span
lang=ES>OrderLineData</span><span style='font-family:宋体'>组件写入数据库：</span></p>

<p class=2 style='margin-top:8.15pt;margin-right:0cm;FTEL:0cm;
margin-left:21.45pt;FTEL:.0001pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;
OrderLineData updateOrderLine = new OrderLineData();</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;
foreach (OrderLine orderLine in order.OrderLines)</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;
{</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
updateOrderLine.Insert(order.OrderId, orderLine);</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;
}</span></p>

<p class=2 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp; }</span></p>

<p class=MsoNormal><span style='font-family:宋体'>最后，无论</span><span lang=ES>try</span><span
style='font-family:宋体'>块中的代码成功执行，还是发生了异常，都会断开连接。</span></p>

<p class=2 style='margin-top:8.15pt;margin-right:0cm;FTEL:0cm;
margin-left:21.45pt;FTEL:.0001pt;FTEL:27.65pt'><span lang=ES>&nbsp;
finally</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;
{</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
connection.Close();</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;
}</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
}</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>}</span></p>

<p class=2 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>}</span></p>

<h4 style='FTEL:21.45pt'><span lang=EN-US>4. OrderLineData</span><span
style='font-family:黑体'>组件</span></h4>

<p class=MsoNormal><span lang=ES>OrderLineData</span><span style='font-family:
宋体'>组件的实现类似于</span><span lang=ES>OrderData</span><span style='font-family:宋体'>组件的实现</span><span
style='font-family:宋体'>。使用属性</span><span lang=ES>[ConstructionEnables]</span><span
style='font-family:宋体'>定义数据库连接字符串</span><span style='font-family:宋体'>：</span></p>

<p class=2 style='margin-top:8.15pt;margin-right:0cm;FTEL:0cm;
margin-left:21.45pt;FTEL:.0001pt;FTEL:18.45pt'><span lang=ES>using
System;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>using
System.EnterpriseServices;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>using
System.Data;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>using
System.Data.SqlClient;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>namespace
Wrox.ProCSharp.EnterpriseServices</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>{</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
public interface IOrderLineUpdate</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
{</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;
void Insert(int orderId, OrderLine orderDetail);</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;
}</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>&nbsp;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>[Transaction(TransactionOption.Required)]</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>[EventTrackingEnabled(true)]</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>[ConstructionEnabled(true,
Default=&quot;server=localhost;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:55.6pt'><span lang=ES>database=northwind;
&quot;trusted_connection=true&quot;)]</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>public
class OrderLineData : ServicedComponent, IOrderLineUpdate</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>{</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>&nbsp;
private string connectionString = null;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>&nbsp;</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>&nbsp;
protected override void Contruct(string s)</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>&nbsp;
{</span></p>

<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=ES>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
connectionString = s;</span></p>

<p class=2 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:27.65pt'><span lang=ES>&nbsp; }</span></p>

<p class=MsoNormal><span style='font-family:宋体'>在</span><span lang=ES>OrderLineData</span><span
style='font-family:宋体'>类的</span><span lang=ES>Insert()</span><span
style='font-family:宋体'>方法中</span><span style='font-family:宋体'>，不使用</span><span
lang=ES>[AutoComplete]</span><span style='font-family:宋体'>属性作为描述定义事务处理结果的另一种方式，而是说明如何使用</span><span
lang=ES>ContextUtil</span><span style='font-family:宋体'>类设置</span><span lang=ES>consistent</span><span
style='font-family:宋体'>和</span><span lang=ES>done</span><span style='font-family:
宋体'>位。在</span><span lang=ES>Insert()</span><span style='font-family:宋体'>方法的最后，根据在数据库中插入数据是否成功，来调用方法</span><span
lang=ES>SetComplete()</span><span style='font-family:宋体'>。万一出现了错误，抛出了异常，方法</span><span
lang=ES>SetAbort()</span><span style='font-family:宋体'>就把</span><span lang=ES>consistent</span><span
style='font-family:宋体'>位设置为</span><span lang=ES>false</span><span
style='font-family:宋体'>，这样事务处理就和所有参与该事务处理的组件一起撤销。</span></p>