Add Table to XML file using Dataset...

  • Thread starter Thread starter Greg
  • Start date Start date
G

Greg

Hello,

I am try to edit an xml file via DataSet in my C# app, by adding a new
table to the structure with multiple nodes to the structure - but the
table should be a child table of one of the existing Tables in the
structure I have read in.

In other words:
<ParentTable>
<Data1>FOO</Data1>
</ParentTable>

Should end up like this:
<ParentTable>
<Data1>FOO</Data1>
<MyChildTable>
<Test>BAR</Test>
</MyChildTable>
</ParentTable>

I'm having problems getting the table in the correct place when I
write the XML after I change it. I am adding the table/fields/
records, and setting up the relations, but for some reason when I
process the xml the new table I have added just appends to the end of
the xml file and doesnt appear in the branch where it should.

Here is the code snippet of what I'm doing:
XmlTextReader xmlreader1 = new XmlTextReader("Test.xml");

DataSet ds = new DataSet();
ds.ReadXml(xmlreader1);

DataTable newTable = new DataTable();
newTable.TableName = "MyChildTable";
newTable.Columns.Add( "NewField" );
newTable.Columns.Add( "ParentTable_ID",System.Type.GetType
("System.Int32") );
ds.Tables.Add( newTable );

ds.Tables["MyChildTable"].ParentRelations.Add( "MyChildTable",
ds.Tables["ParentTable"].Columns["ParentTable_ID"], ds.Tables
["MyChildTable"].Columns["ParentTable_ID"], true);

DataRow newRow;
newRow = ds.Tables["MyChildTable"].NewRow();
newRow["Test"] = "Value";
newRow["ParentTable_ID"] = "1";
ds.Tables["MyChildTable"].Rows.Add(newRow);

ds.AcceptChanges();

StreamWriter myStreamWriter = new StreamWriter("Out.xml" );
ds.WriteXml(myStreamWriter);
myStreamWriter.Close();


Can anyone see what I am doing incorrectly or have any suggestions?

Thanks,
Greg
(e-mail address removed)
 
I would strongly recommend writing a second (related) table, and not do
nesting.
<ParentTable>
<Data1>FOO</Data1>
</ParentTable>

<MyChildTable>
Click to expand...
<Test>BAR1</Test>
</MyChildTable>
<MyChildTable>
Click to expand...
<Test>BAR2</Test>
</MyChildTable>
Click to expand...

Where Data1 is the relation.


I've never been successful with nested tables in a DataSet.

Maybe someone else has? But not me.





Greg said:
Hello,

I am try to edit an xml file via DataSet in my C# app, by adding a new
table to the structure with multiple nodes to the structure - but the
table should be a child table of one of the existing Tables in the
structure I have read in.

In other words:
<ParentTable>
<Data1>FOO</Data1>
</ParentTable>

Should end up like this:
<ParentTable>
<Data1>FOO</Data1>
<MyChildTable>
<Test>BAR</Test>
</MyChildTable>
</ParentTable>

I'm having problems getting the table in the correct place when I
write the XML after I change it. I am adding the table/fields/
records, and setting up the relations, but for some reason when I
process the xml the new table I have added just appends to the end of
the xml file and doesnt appear in the branch where it should.

Here is the code snippet of what I'm doing:
XmlTextReader xmlreader1 = new XmlTextReader("Test.xml");

DataSet ds = new DataSet();
ds.ReadXml(xmlreader1);

DataTable newTable = new DataTable();
newTable.TableName = "MyChildTable";
newTable.Columns.Add( "NewField" );
newTable.Columns.Add( "ParentTable_ID",System.Type.GetType
("System.Int32") );
ds.Tables.Add( newTable );

ds.Tables["MyChildTable"].ParentRelations.Add( "MyChildTable",
ds.Tables["ParentTable"].Columns["ParentTable_ID"], ds.Tables
["MyChildTable"].Columns["ParentTable_ID"], true);

DataRow newRow;
newRow = ds.Tables["MyChildTable"].NewRow();
newRow["Test"] = "Value";
newRow["ParentTable_ID"] = "1";
ds.Tables["MyChildTable"].Rows.Add(newRow);

ds.AcceptChanges();

StreamWriter myStreamWriter = new StreamWriter("Out.xml" );
ds.WriteXml(myStreamWriter);
myStreamWriter.Close();


Can anyone see what I am doing incorrectly or have any suggestions?

Thanks,
Greg
(e-mail address removed)
Click to expand...
 
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