此Microsoft Visual Basic 應用程式會使用 ADO 來建立與 Microsoft SQL Server 實例的連線,並執行 updategram。 Updategram 會更新特定員工的姓氏。 此範例使用 AdventureWorks 範例資料庫。
在這裡範例應用程式中:
conn 物件 (ADODB.連接) 會在特定伺服器電腦上建立與執行中 SQL Server 實例的連線。
Cmd 物件 (ADODB.命令) 會在已建立的連接上執行。
命令方言會設定為 DBGUID_MSSQLXML。
updategram 會複製到命令數據流 (strmIn)。
命令的輸出數據流會設定為 StrmOut 物件 (ADODB。數據流) 以接收任何傳回的數據。
最後會執行命令 (updategram)。
以下是範例程式代碼:
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
備註
如果您使用來自 ADO 的 SQLXML 來執行指定 XSD 架構的 updategram,則必須在連接物件上將 「SQLXML Version屬性設定為」SQLXML.4.0,如下列程式代碼範例行所示:
conn.Properties("SQLXML Version") = "SQLXML.4.0"
指定 Updategram 的對應架構
此範例說明如何在 Updategram 中指定和使用對應架構。
將下列 XSD 架構 (EmpSchema.xml) 儲存至磁碟,並確定將程式代碼中指定的路徑更新至磁碟上對應架構的位置。 程式代碼假設架構儲存在 [架構] 資料夾中的 C: 磁碟驅動器上。
<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>
因為可以同時指定 XSD 和 XDR 架構,因此這是相等的 XDR 架構:
<?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>
這是 Visual Basic 程式代碼,可執行具有相關聯對應架構的 Updategram。 Updategram 會更新 Person.Contact 數據表中聯繫人 1 的中間名。
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
傳遞參數
在稍早提供的 Visual Basic 應用程式中,不會傳遞參數。 在此應用程式中, ContactID 和 MiddleName 值會當做參數化輸入傳遞至 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