最后要介绍的是ADO 2.6机制,该机制是在VB 6.0中实现的。我们先创建一个名为DBXMLVS6的ActiveX DLL项目,然后把Class1修改为ADO26,接着添加一个到ActiveX Data Objects 2.6的引用。一旦完毕,为该类添加一个ExecuteSelect()方法如下:
Public Function ExecuteSelect(
CustomerID As String,
ConnectionString As String)
As String
Set conn = New ADODB.Connection
conn.ConnectionString = ConnectionString
conn.Open
Set cmd = New ADODB.Command
cmd.ActiveConnection = conn
cmd.CommandText = "select * from customers
where CustomerID = '" & CustomerID & "'"
Set rs = cmd.Execute
Set adoStream = New ADODB.Stream
adoStream.Type = adTypeText
adoStream.Open
rs.Save adoStream, adPersistXML
'返回XML字符串
ExecuteSelect = adoStream.ReadText()
End Function
using (SqlConnection cn = new SqlConnection(connectionString))
{
cn.Open();
//call the overload that takes a connection in place of the connection string
return ExecuteNonQuery(cn, commandType, commandText, commandParameters);
}