Question

如何使用vb.net从数据库创建XML文件正如我尝试的那样，我只创建了根元素而不是数据库中的任何数据，而我的代码是：

<% @Import Namespace="System" %>
<% @Import Namespace="System.Data" %>
<% @Import Namespace="System.xml" %>
<% @Import Namespace="System.Data.SqlClient" %>

<Script runat="server">
Sub Page_Load

Dim connectionString As String
Dim connection As SqlConnection
Dim adapter As SqlDataAdapter
Dim ds  As New DataSet
Dim sql As String

connectionString =// my connection string///
connection = New SqlConnection(connectionString) 


sql = "select * from jb_jobs where city='Los Angeles' "
connection.Open()
adapter = New SqlDataAdapter(sql, connection)
adapter.Fill(ds)
connection.Close()
If IO.File.Exists("product.xml") = False Then
Dim settings As New XmlWriterSettings()
settings.Indent = True
Dim XmlWrt As XmlWriter = XmlWriter.Create("c:/xmlfiles/product.xml", settings)
XmlWrt.WriteStartDocument()
XmlWrt.WriteComment("XML Database.")
XmlWrt.WriteStartElement("source")
XmlWrt.WriteStartElement("jobs")



XmlWrt.WriteEndElement()
XmlWrt.WriteEndDocument()
XmlWrt.Close()
End If
End Sub
</script>

我得到的输出只是一个XML文件，只用上面描述的根元素创建，而不是数据库中的数据。

如何从数据库中获取数据并形成XML文件？

Answer 1

尝试使用WriteXml方法，如下所示：

Private Sub WriteXmlToFile(thisDataSet As DataSet)
 If thisDataSet Is Nothing Then 
     Return 
 End If  

' Create a file name to write to. 
 Dim filename As String = "XmlDoc.xml" 

 ' Create the FileStream to write with. 
 Dim stream As New System.IO.FileStream _
    (filename, System.IO.FileMode.Create)

 ' Write to the file with the WriteXml method.
 thisDataSet.WriteXml(stream)
End Sub

您可以在MSDN上找到有关DataTable.WriteXml和DataSet.WriteXml的更多信息。

Answer 2

所以你应该问过从数据库中检索数据＆＃39; ??

如何更改sql语句：

sql =＆＃34;从jb_jobs中选择*其中city =＆＃39; Los Angeles＆＃39; ＆＃34;

到

sql =＆＃34;从jb_jobs中选择*城市LIKE＆＃39; Los Angeles＆＃39;＆＃34; - ＆GT;串

或

sql =＆＃34;从jb_jobs中选择*，其中city = CityID＆＃34; - ＆GT;整数

如何在vb.net中从数据库创建XML文件

2 个答案: