Question

I was given an .xml file that I needed to read into my code as a DataSet (as background, the file was created by creating a DataSet in C# and calling dataSet.WriteXml(file, XmlWriteMode.IgnoreSchema), but this was done by someone else).

The .xml file was shaped like this:

 <?xml version='1.0' standalone='yes'?>  <NewDataSet>   <Foo>     <Bar>abcd</Bar>     <Foo>efg</Foo>   </Foo>   <Foo>     <Bar>hijk</Bar>     <Foo>lmn</Foo>   </Foo> </NewDataSet> 

Using C# and .NET 2.0, I read the file in using the code below:

        DataSet ds = new DataSet();         ds.ReadXml(file); 

Using a breakpoint, after this line ds.Tables[0] looked like this (using dashes in place of underscores that I couldn’t get to format properly):

Bar     Foo-Id    Foo-Id-0 abcd     0         null null     1         0 hijk     2         null null     3         2 

I have found a workaround (I know there are many) and have been able to successfully read in the .xml, but what I would like to understand why ds.ReadXml(file) performed in this manner, so I will be able to avoid the issue in the future. Thanks.

Answer 1

This appears to be correct for your nested Foo tags:

<NewDataSet>     <Foo>              <!-- Foo-Id: 0 -->     <Bar>abcd</Bar>     <Foo>efg</Foo>   <!-- Foo-Id: 1, Parent-Id: 0 -->   </Foo>   <Foo>              <!-- Foo-Id: 2 -->     <Bar>hijk</Bar>     <Foo>lmn</Foo>   <!-- Foo-Id: 3, Parent-Id: 2 -->   </Foo> </NewDataSet> 

So this correctly becomes 4 records in your result, with a parent-child key of ‘Foo-Id-0’

Try:

<NewDataSet>     <Rec>              <!-- Rec-Id: 0 -->     <Bar>abcd</Bar>     <Foo>efg</Foo>      </Rec>   <Rec>              <!-- Rec-Id: 1 -->     <Bar>hijk</Bar>     <Foo>lmn</Foo>      </Rec> </NewDataSet> 

Which should result in:

Bar     Foo        Rec-Id abcd    efg        0 hijk    lmn        1