嗨朋友们希望一切顺利。我使用vb.net（即"Conversion from type 'DBNull' to type 'String' is not valid"使用数据表从xml文件将数据保存到sql server数据库时遇到一个问题。但并不总是得到错误可能基于xml文件。下面是我的一个xml文件。我曾经随机生成xml文件。
<Jobs>
- <Job ID="895562" PositionID="2300056">
<Title>Senior Network Administrator</Title>
- <Summary>
- <![CDATA[ Join a global leader in an exciting Australia and New Zealand role. As the Leader of Technical Support you will be responsible for mentoring and managing a technical team striving to become the technical centre of excellence in the region. A hands on role, you will not only be the technical expert but you will work along side the sales team and directly contribute to the growth of the business. Th
]]>
</Summary>
<DateActive Date="2009-10-15T19:06:00-05:00">10/15/2009</DateActive>
<DateExpires Date="2009-11-14T19:06:00-05:00">11/14/2009</DateExpires>
<DateUpdated Date="2009-10-15 19:06:00">10/15/2009</DateUpdated>
<Country>xxxx</Country>
<State>xxx</State>
<City>xxx</City>
<PostalCode>888899</PostalCode>
<Min Value="90000">90,000.00</Min>
<Max Value="100000">100,000.00</Max>
<Type ID="1">Per Year</Type>
<Currency ID="4">xxx</Currency>
<BuilderFields />
<DisplayOptions>4</DisplayOptions>
<AddressType>6</AddressType>
</Job>
- <Job ID="84000527" PositionID="61383275">
<Title>QA Test Analyst- Banking and Finance</Title>
- <Summary>
- <![CDATA[ Extensive background in QA testing within the finance sector essential ISEB Testing qualification essential About our Client Our client is a leading global banking organisation Job Description In this role you will be responsible for systems integration testing, Quality Assurance and Environment support for a wide variety of technology projects. Responsibilities will include: Working closely with d
]]>
</Summary>
<DateActive Date="2009-10-15T18:31:11-05:00">10/15/2009</DateActive>
<DateExpires Date="2009-11-14T20:00:35-05:00">11/14/2009</DateExpires>
<DateUpdated Date="2009-10-15 20:01:00">10/15/2009</DateUpdated>
<Country>xxx</Country>
<City>xxx</City>
<PostalCode>8888</PostalCode>
<Min Value="90000">90,000.00</Min>
<Max Value="100000">100,000.00</Max>
<Type ID="1">Per Year</Type>
<Currency ID="4">xxx</Currency>
<CompanyName>Michael Page International</CompanyName>
<BuilderFields />
<DisplayOptions />
<AddressType>6</AddressType>
</Job>
<Job ID="895562" PositionID="2300056">
<Title>Senior Network Administrator</Title>
- <Summary>
- <![CDATA[ Join a global leader in an exciting Australia and New Zealand role. As the Leader of Technical Support you will be responsible for mentoring and managing a technical team striving to become the technical centre of excellence in the region. A hands on role, you will not only be the technical expert but you will work along side the sales team and directly contribute to the growth of the business. Th
]]>
</Summary>
<DateActive Date="2009-10-15T19:06:00-05:00">10/15/2009</DateActive>
<DateExpires Date="2009-11-14T19:06:00-05:00">11/14/2009</DateExpires>
<DateUpdated Date="2009-10-15 19:06:00">10/15/2009</DateUpdated>
<Country>xxxx</Country>
<State>xxx</State>
<City>xxx</City>
<PostalCode>888899</PostalCode>
<Min Value="90000">90,000.00</Min>
<Max Value="100000">100,000.00</Max>
<Type ID="1">Per Year</Type>
<Currency ID="4">xxx</Currency>
<BuilderFields />
<DisplayOptions>4</DisplayOptions>
<AddressType>6</AddressType>
</Job>
</Jobs>
PLS。帮助我克服这个问题。提前致谢。 ++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++ =
Protected Sub lnkbtnUpload_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim fid, filename As String
fid = CType(sender.parent.controls(0).parent.parent.controls(0), TableCell).Text
filename = fid & ".xml"
Dim uploadDS As New DataSet
Dim tempDT As New DataTable
Dim i As Integer
Dim ConeFilePath As String = Nothing
ConeFilePath = "~/CareerOneModifiedFeeds/" & filename.ToString()
uploadDS.ReadXml(Server.MapPath(ConeFilePath))
tempDT = uploadDS.Tables(0).DefaultView.ToTable
Dim dtRow As DataRow
Dim JobCount As Integer
Dim Count As Integer = 0
Dim strsaltype, strsalcur As String
Dim strMinSal, strMaxSal As String
For i = 0 To tempDT.Rows.Count - 1
Count = Count + 1
dtRow = tempDT.Rows(i)
'Code to get the check whether the job id already exists or not
JobCount = Dr.CheckJobIDExists(UserID, Trim(dtRow.Item("JOB_ID")))
Dim FullLoc As String = Replace(dtRow.Item("COUNTRY"), "'", "''").Trim() + "-" + Replace(dtRow.Item("STATE"), "'", "''").Trim()
If dtRow.Item("CITY") <> "" Then
FullLoc = FullLoc + "-" + Replace(dtRow.Item("CITY"), "'", "''").Trim()
End If
If JobCount = 1 Then
' Update the record aganist that jobid
DR.UpdateExistingCareerOneJobs_XML(UserID, Trim(dtRow.Item("JOB_ID")), Trim(Replace(dtRow.Item("TITLE"), "'", "''")), _
Trim(Replace(dtRow.Item("Summary"), "'", "''")), Trim(Replace(dtRow.Item("DateActive"), "'", "''")), _
Trim(Replace(dtRow.Item("DateExpire"), "'", "''")), FullLoc, Trim(Replace(dtRow.Item("COUNTRY"), "'", "''")), _
Trim(Replace(dtRow.Item("STATE"), "'", "''")), Trim(Replace(dtRow.Item("CITY"), "'", "''")), Trim(Replace(dtRow.Item("PostalCode"), "'", "''")), _
Trim(Replace(dtRow.Item("BuilderFields"), "'", "''")), Trim(Replace(dtRow.Item("DisplayOptions"), "'", "''")), _
Trim(Replace(dtRow.Item("AddressType"), "'", "''")), Trim(Replace(dtRow.Item("CompanyName"), "'", "''")), _
Trim(Replace(dtRow.Item("PositionID"), "'", "''")), Trim(Replace(dtRow.Item("SalMin"), "'", "''")), Trim(Replace(dtRow.Item("SalMax"), "'", "''")), _
Trim(Replace(dtRow.Item("SalType"), "'", "''")), Trim(Replace(dtRow.Item("SalCurrency"), "'", "''")), Replace(JobCat, "'", "''"), DateTime.Now())
Else
' Insert record new jobid
Dim z As Integer = DR.InsertCareeroneJobs_XML(UserID, Trim(dtRow.Item("JOB_ID")), Trim(Replace(dtRow.Item("TITLE"), "'", "''")), _
Trim(Replace(dtRow.Item("Summary"), "'", "''")), Trim(Replace(dtRow.Item("DateActive"), "'", "''")), _
Trim(Replace(dtRow.Item("DateExpire"), "'", "''")), FullLoc, Trim(Replace(dtRow.Item("COUNTRY"), "'", "''")), _
Trim(Replace(dtRow.Item("STATE"), "'", "''")), Trim(Replace(dtRow.Item("CITY"), "'", "''")), _
Trim(dtRow.Item("PostalCode")), Trim(Replace(dtRow.Item("BuilderFields"), "'", "''")), _
Trim(Replace(Convert.ToString(dtRow.Item("DisplayOptions")), "'", "''")), Trim(Replace(dtRow.Item("AddressType"), "'", "''")), _
Trim(Replace(dtRow.Item("CompanyName"), "'", "''")), Trim(Replace(dtRow.Item("PositionID"), "'", "''")), Trim(strsaltype.ToString()), _
Trim(strsalcur.ToString()), Trim(Replace(Convert.ToString(JobCat), "'", "''")), strMinSal, strMaxSal, DateTime.Now())
' Trim(Replace(dtRow.Item("PositionID"), "'", "''")),Trim(strsaltype.ToString()), Trim(strsalcur.ToString()), _
Response.Write(z)
End If
Next i
End Sub
答案 0 :(得分：0)
您可以尝试以下storedproc，您可以在其中发送xml文件的xml内容并插入到表中。访问此link
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE JobsBulkInsertXML @items xml
AS
DECLARE @hDoc int
exec sp_xml_preparedocument @hDoc OUTPUT, @items
Insert Into absorbentorder
SELECT dpc, absorbentcode, quantity
FROM OPENXML (@hDoc, '/absorbentitems',1)
WITH (dpc char(15), absorbentcode char(15), quantity char(15)) XMLItems
EXEC sp_xml_removedocument @hDoc
GO
答案 1 :(得分：0)
我不认为这是您的SQL代码的问题 - 但在处理可能包含空字段的数据行时，您需要在vb.net代码中小心：
Trim(Replace(dtRow.Item("DateExpire"), "'", "''"))
Trim(Replace(dtRow.Item("COUNTRY"), "'", "''"))
如果Replace（或您使用的任何一个）为空/ NULL，则对dtRow.Item("COUNTRY")的所有这些调用可能会落在他们的鼻子上。
您需要更加小心地应用这些方法并首先检查DBNull.Value！
创建一个这样的函数（在C＃中 - 将它转换为VB.NET应该没有问题）：
public string ReplaceString(DataRow row, string fieldname)
{
// first make sure the value of the field in the row is not NULL !
if(!row.IsNull(fieldname))
{
// only if NOT null, do the replace
return row[fieldname].Replace("'", "''").Trim();
}
// if the field is DBNull, return an empty string
return string.Empty;
}
然后使用它代替您对Trim(Replace(...))的显式调用。
马克