Help with DataRelationCollection indexer

[Jeff Higgins]

In the code below, when I use the integer indexer I get the correct output.

DataRelation myRelation = ds.Tables["TestDocument"].ChildRelations[0];
Output:
No.1TestItems
No.2TestItems

But when I use the string indexer the output is nil.

DataRelation myRelation =
ds.Tables["TestDocument"].ChildRelations["RelationDocumentItems"];
Output:

Will someone help me understand what I'm doing wrong?
Thanks,
Jeff Higgins


using System;
using System.Data;
using System.Xml;
using System.Text;
using System.Windows.Forms;

namespace xmltest
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
StringBuilder s = new StringBuilder();

DataSet ds = new DataSet();
ds.ReadXml("test.xml", XmlReadMode.Auto);

DataRelation myRelation =
ds.Tables["TestDocument"].ChildRelations["RelationDocumentItems"];
DataTable myTable = ds.Tables["TestDocument"];
DataRow[] arrRows;
foreach(DataRow myRow in myTable.Rows)
{
arrRows = myRow.GetChildRows(myRelation, DataRowVersion.Current);
for(int i = 0; i < arrRows.Length; i++)
{
s.Append(arrRows["name"] + "\n");
}
}
MessageBox.Show(s.ToString(), "Menu Data", MessageBoxButtons.OK);
}
}
}


<?xml version="1.0" encoding="utf-8"?>
<TestDocument xmlns="http://tempuri.org/test.xsd"
me="{E292E134-BEC8-49f7-A1E8-C3580C76C5B8}" name="TestDocument">
<TestItems me="{3738B467-C142-4ece-88B6-666327FA37B0}"
owner="{E292E134-BEC8-49f7-A1E8-C3580C76C5B8}" name="No.1TestItems">
<TestItem me="{72C372F3-4E96-4a82-892B-B441E42D77B6}"
owner="{3738B467-C142-4ece-88B6-666327FA37B0}" name="No.1FirstTestItem" />
<TestItem me="{BEB920DF-C2BA-46cf-8E59-EB060E2715DD}"
owner="{3738B467-C142-4ece-88B6-666327FA37B0}" name="No.1SecondTestItem" />
<TestItem me="{3776230C-0669-4be4-BBFB-1D50789320D4}"
owner="{3738B467-C142-4ece-88B6-666327FA37B0}" name="No.1ThirdTestItem" />
</TestItems>
<TestItems me="{560223A6-0938-4a3b-89CD-9507F1F26682}"
owner="{E292E134-BEC8-49f7-A1E8-C3580C76C5B8}" name="No.2TestItems">
<TestItem me="{2AA34205-3695-4f2c-9DF0-C3D0EA9E1AF2}"
owner="{560223A6-0938-4a3b-89CD-9507F1F26682}" name="No.2FirstTestItem" />
<TestItem me="{3EC22224-B0BE-4364-A631-F455AD2E6F61}"
owner="{560223A6-0938-4a3b-89CD-9507F1F26682}" name="No.2SecondTestItem" />
<TestItem me="{8FC33219-4104-458e-A08A-8A5DB549DD50}"
owner="{560223A6-0938-4a3b-89CD-9507F1F26682}" name="No.2ThirdTestItem" />
</TestItems>
</TestDocument>


<?xml version="1.0" ?>
<xs:schema id="NewDataSet" targetNamespace="http://tempuri.org/test.xsd"
xmlns:mstns="http://tempuri.org/test.xsd"
xmlns="http://tempuri.org/test.xsd"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:msdata="urn:schemas-microsoft-com:xml-msdata"
attributeFormDefault="qualified" elementFormDefault="qualified">
<xs:element name="TestDocument">
<xs:complexType>
<xs:sequence>
<xs:element name="TestItems" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="TestItem" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="me" form="unqualified" type="xs:string" />
<xs:attribute name="owner" form="unqualified" type="xs:string" />
<xs:attribute name="name" form="unqualified" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="me" form="unqualified" type="xs:string" />
<xs:attribute name="owner" form="unqualified" type="xs:string" />
<xs:attribute name="name" form="unqualified" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="me" form="unqualified" type="xs:string" />
<xs:attribute name="name" form="unqualified" type="xs:string" />
</xs:complexType>
<xs:key name="KeyPrimaryTestDocument" msdatarimaryKey="true">
<xs:selector xpath="." />
<xs:field xpath="@me" />
</xs:key>
<xs:key name="KeyPrimaryTestItems" msdatarimaryKey="true">
<xs:selector xpath=".//mstns:TestItems" />
<xs:field xpath="@me" />
</xs:key>
<xs:key name="KeyPrimaryTestItem" msdatarimaryKey="true">
<xs:selector xpath=".//mstns:TestItem" />
<xs:field xpath="@me" />
</xs:key>
<xs:keyref name="RelationDocumentItems"
refer="mstns:KeyPrimaryTestDocument">
<xs:selector xpath=".//mstns:TestItems" />
<xs:field xpath="@owner" />
</xs:keyref>
<xs:keyref name="RelationItemsItem" refer="mstns:KeyPrimaryTestItems">
<xs:selector xpath=".//mstns:TestItem" />
<xs:field xpath="@owner" />
</xs:keyref>
</xs:element>
<xs:element name="NewDataSet" msdata:IsDataSet="true"
msdata:EnforceConstraints="False">
<xs:complexType>
<xs:choice maxOccurs="unbounded">
<xs:element ref="TestDocument" />
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>

 

[Jeff Higgins]

If I do:
DataRelation myRelation = ds.Tables["TestDocument"].ChildRelations[0];
s.Append(myRelation.ToString());

I get in s:
TestDocument_TestItems

rather than the expected:
RelationDocumentItems

Where does that come from?
Thanks,
Jeff Higgins

 

[Jeff Higgins]

Maybe my schema is not being read, instead ReadXml() is infering a schema?

Any help will much appreciated.
Thanks
Jeff Higgins

 

[Jeff Higgins]

Thank you, Addison Wesley Professional and Shawn Wildermuth

for the sample chapter titled Typed DataSets in ADO.NET
from your book titled Pragmatic ADO.NET: Data Access for the Internet World
ISBN: 0201745682

located at:

http://www.awprofessional.com/articles/article.asp?p=30593


Thank you,

Addison Wesley Professional and Bob Beauchemin

for the sample chapter titled Essential ADO.NET: XML and Data Access
Integration
from your book titled Essential ADO.NET ISBN: 0201758660

and located at:

http://www.awprofessional.com/articles/article.asp?p=29901