使用 ADO 执行 Updategram （SQLXML 4.0）

2017-03-06

此Microsoft Visual Basic 应用程序使用 ADO 与 Microsoft SQL Server 实例建立连接，并执行 updategram。 updategram 更新特定员工的姓氏。此示例使用 AdventureWorks 示例数据库。

在此示例应用程序中：

conn 对象（ADODB.连接）与特定服务器计算机上的 SQL Server 正在运行的实例建立连接。
cmd 对象（ADODB）。命令）在已建立的连接上执行。
命令方言设置为DBGUID_MSSQLXML。
updategram 将复制到命令流（strmIn）。
命令的输出流设置为 StrmOut 对象（ADODB）。流）接收任何返回的数据。
最后执行命令（updategram）。

下面是示例代码：

Private Sub Form_Load()  
  
  Dim cmd As New ADODB.Command  
  Dim conn As New ADODB.Connection  
  Dim strmIn As New ADODB.Stream  
  Dim strmOut As New ADODB.Stream  
  Dim SQLxml As String  
  
  ' Open a connection to the instance of SQL Server.  
  conn.Provider = "SQLOLEDB"  
  conn.Open "server=(local); database=AdventureWorks; Integrated Security=SSPI; "  
  conn.Properties("SQLXML Version") = "SQLXML.4.0"  
  Set cmd.ActiveConnection = conn  
  
  ' Build the command string in the form of an XML template.  
    SQLxml = "<ROOT xmlns:updg='urn:schemas-microsoft-com:xml-updategram' >"  
    SQLxml = SQLxml & "  <updg:sync updg:nullvalue='IsNULL'>"  
    SQLxml = SQLxml & "    <updg:before>"  
    SQLxml = SQLxml & "       <Person.Contact ContactID='64' Title='IsNULL'/>"  
    SQLxml = SQLxml & "    </updg:before>"  
    SQLxml = SQLxml & "    <updg:after>"  
    SQLxml = SQLxml & "       <Person.Contact ContactID='64' Title='Mr.'/>"  
    SQLxml = SQLxml & "    </updg:after>"  
    SQLxml = SQLxml & "  </updg:sync>"  
    SQLxml = SQLxml & "</ROOT>"  
  
  ' Set the command dialect to DBGUID_MSSQLXML.  
  cmd.Dialect = "{5d531cb2-e6ed-11d2-b252-00c04f681b71}"  
  
  ' Open the command stream and write our template to it.  
  strmIn.Open  
  strmIn.WriteText SQLxml  
  strmIn.Position = 0  
  
  Set cmd.CommandStream = strmIn  
  
  ' Execute the command, open the return stream, and read the result.  
  strmOut.Open  
  strmOut.LineSeparator = adCRLF  
  cmd.Properties("Output Stream").Value = strmOut  
  cmd.Properties("Output Encoding").Value = "UTF-8"  
  cmd.Execute , , adExecuteStream  
  strmOut.Position = 0  
  Debug.Print strmOut.ReadText  
  strmOut.Close  
  strmIn.Close  
  
End Sub

注释

如果使用 ADO 中的 SQLXML 执行指定 XSD 架构的 updategram，则必须在连接对象上将“SQLXML Version”属性设置为“”SQLXML.4.0，如以下示例代码行所示：

conn.Properties("SQLXML Version") = "SQLXML.4.0"

指定 Updategram 的映射架构

此示例演示如何在 updategram 中指定和使用映射架构。

将以下 XSD 架构（EmpSchema.xml）保存到磁盘，并确保将代码中指定的路径更新到磁盘上的映射架构的位置。该代码假定架构保存在 Schemas 文件夹中的 C：驱动器上。

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"  
            xmlns:sql="urn:schemas-microsoft-com:mapping-schema">  
  <xsd:element name="Contact" sql:relation="Person.Contact" >  
   <xsd:complexType>  
        <xsd:attribute name="CID"    
                       sql:field="ContactID"   
                       type="xsd:string" />   
        <xsd:attribute name="MName"    
                       sql:field="MiddleName"    
                       type="xsd:string" />  
    </xsd:complexType>  
  </xsd:element>  
</xsd:schema>

由于可以指定 XSD 和 XDR 架构，因此这是等效的 XDR 架构：

<?xml version="1.0" ?>  
   <Schema xmlns="urn:schemas-microsoft-com:xml-data"   
         xmlns:dt="urn:schemas-microsoft-com:datatypes"   
         xmlns:sql="urn:schemas-microsoft-com:xml-sql">  
     <ElementType name="Contact" sql:relation="Person.Contact" >  
       <AttributeType name="CID" />  
       <AttributeType name="MName" />  
  
       <attribute type="CID" sql:field="ContactID" />  
       <attribute type="MName" sql:field="MiddleName" />  
     </ElementType>  
   </Schema>

这是用于执行具有关联映射架构的 updategram 的 Visual Basic 代码。 updategram 更新 Person.Contact 表中联系人 1 的中间名称。

Private Sub Form_Load()  
    Dim cmd As New ADODB.Command  
    Dim conn As New ADODB.Connection  
    Dim strmIn As New ADODB.Stream  
    Dim strmOut As New ADODB.Stream  
  
    ' Open a connection to the SQL Server.  
    conn.Provider = "SQLOLEDB"  
    conn.Open "server=(local); database=AdventureWorks; Integrated Security='SSPI' ;"  
    conn.Properties("SQLXML Version") = "SQLXML.4.0"  
    Set cmd.ActiveConnection = conn  
  
    ' Open the command stream and write the template to it.  
    strmIn.Open  
    strmIn.WriteText "<ROOT xmlns:updg='urn:schemas-microsoft-com:xml-updategram' >"  
    strmIn.WriteText "  <updg:sync mapping-schema='C:\Schemas\EmpSchema.xml' >"  
    strmIn.WriteText "      <updg:before>"  
    strmIn.WriteText "          <Contact CID='1' />"  
    strmIn.WriteText "      </updg:before>"  
    strmIn.WriteText "      <updg:after>"  
    strmIn.WriteText "          <Contact MName='M.'/>"  
    strmIn.WriteText "      </updg:after>"  
    strmIn.WriteText "  </updg:sync>"  
    strmIn.WriteText "</ROOT>"  
  
    ' Set the command dialect to XML.  
    cmd.Dialect = "{5d531cb2-e6ed-11d2-b252-00c04f681b71}"  
    strmIn.Position = 0  
    Set cmd.CommandStream = strmIn  
  
    ' Execute the command, open the return stream, and read the result.  
    strmOut.Open  
    strmOut.LineSeparator = adCRLF  
    cmd.Properties("Output Stream").Value = strmOut  
    cmd.Execute , , adExecuteStream  
    strmOut.Position = 0  
    Debug.Print strmOut.ReadText  
    strmOut.Close  
    strmIn.Close  
    conn.Close  
End Sub

传递参数

在前面提供的 Visual Basic 应用程序中，不会传递参数。在此应用程序中， ContactID 和 MiddleName 值作为参数化输入传递给 updategram。

Private Sub Form_Load()  
  
  Dim cmd As New ADODB.Command  
  Dim conn As New ADODB.Connection  
  Dim strmIn As New ADODB.Stream  
  Dim strmOut As New ADODB.Stream  
  Dim InputContactID As String  
  Dim InputMiddleName As String  
  
  InputContactID = "1"  
  InputMiddleName = "Q."  
  
  ' Open a connection to the instance of SQL Server.  
  conn.Provider = "SQLOLEDB"  
  conn.Open "server=(local); database=AdventureWorks; Integrated Security=SSPI; "  
  conn.Properties("SQLXML Version") = "SQLXML.4.0"  
  Set cmd.ActiveConnection = conn  
  
  ' Build the command string in the form of an XML template.  
  SQLxml = "<ROOT xmlns:updg='urn:schemas-microsoft-com:xml-updategram' >"  
  SQLxml = SQLxml & "<updg:header>"  
  SQLxml = SQLxml & "<updg:param name='ContactID'/>"  
  SQLxml = SQLxml & "<updg:param name='MiddleName' />"  
  SQLxml = SQLxml & "</updg:header>"  
  SQLxml = SQLxml & "<updg:sync >"  
  SQLxml = SQLxml & " <updg:before>"  
  SQLxml = SQLxml & "   <Person.Contact ContactID='$ContactID' />"  
  SQLxml = SQLxml & "</updg:before>"  
  SQLxml = SQLxml & "<updg:after>"  
  SQLxml = SQLxml & "<Person.Contact MiddleName='$MiddleName' />"  
  SQLxml = SQLxml & "</updg:after>"  
  SQLxml = SQLxml & "</updg:sync>"  
  SQLxml = SQLxml & "</ROOT>"  
  
  ' Set the command dialect to XML.  
  cmd.Dialect = "{5d531cb2-e6ed-11d2-b252-00c04f681b71}"  
  
  ' Open the command stream and write the template to it.  
  strmIn.Open  
  strmIn.WriteText SQLxml  
  strmIn.Position = 0  
  
  Set cmd.CommandStream = strmIn  
  
  ' Execute the command, open the return stream, and read the result.  
  strmOut.Open  
  strmOut.LineSeparator = adCRLF  
  cmd.NamedParameters = True  
  cmd.Parameters.Append cmd.CreateParameter("@ContactID", adBSTR, adParamInput, 1, InputContactID)  
  cmd.Parameters.Append cmd.CreateParameter("@MiddleName", adBSTR, adParamInput, 7, InputMiddleName)  
  cmd.Properties("Output Stream").Value = strmOut  
  cmd.Execute , , adExecuteStream  
  strmOut.Position = 0  
  Debug.Print strmOut.ReadText  
  
End Sub

通过

使用 ADO 执行 Updategram （SQLXML 4.0）

指定 Updategram 的映射架构

传递参数

其他资源