Hi,

I would appreciate if someone could help me to solve this problem.

I am trying to use a dataset to generate nested XML but am getting the following error:

"Cannot proceed with serializing DataTable 'Order Details'. It contains a DataRow which has multiple parent rows on the same Foreign Key."

I had a look at the Northwind database to try and figure out what that message means and I think that the problem is related to the fact that the [Order Detail] table has a composite primary key OrderID and ProductID.

Example :

Customer Orders Order Detail Products
-------------- ---------- ----------------- -------------
CustomerID OrderID OrderID ProductID
ProductID

This is the code I am using to set up the relationship:

DataRelation custOrderRel = thisDataSet.Relations.Add("CustOrders",
thisDataSet.Tables["Customers"].Columns["CustomerID"],
thisDataSet.Tables["Orders"].Columns["CustomerID"]);


DataRelation orderDetailRel = thisDataSet.Relations.Add("OrderDetail",
thisDataSet.Tables["Orders"].Columns["OrderID"],
thisDataSet.Tables["Order Details"].Columns["OrderID"]);

DataRelation orderProductRel = thisDataSet.Relations.Add(
"OrderProducts", thisDataSet.Tables["Products"].Columns["ProductID"],
thisDataSet.Tables["Order Details"].Columns["ProductID"]);

thisDataSet.WriteXmlSchema(Server.MapPath("~/xml/Northwind.xsd"));
thisDataSet.WriteXml(Server.MapPath("~/xml/Northwind.xml"));

thisDataSet.Relations["CustOrders"].Nested = true;
thisDataSet.Relations["OrderDetail"].Nested = true;
thisDataSet.Relations["OrderProducts"].Nested = true;

thisDataSet.WriteXml(Server.MapPath("~/xml/nestedNorthwind.xml"));

Cheers

P.

I am sorry. The example got messed up.

These are the tables I am using in the dataset

Customer
--------------
CustomerID

+++++++++++++++++++

Orders
----------
OrderID

++++++++++++++++++++

Order Detail
-----------------
OrderID
ProductID

+++++++++++++++++++++

Products
--------------
ProductID

And this is how they are related:

Customer ----> Order

Order -----> Order Detail <---- Products

Thanks

P

Hi pallone,

Never ran into this error so I don't know the fix, but maybe this helps: http://forums.asp.net/p/1079069/1598048.aspx#1598048

Not really a solution, but at least some work around...

Imar

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Hi Imar,

Thanks for the reply.

I had seen this before and had tried to set the constraints off but it did not work for me.

Basically, I have a many-to-many relationship between Order and Product via a bridge table called OrderDetail.

The bridge table's primary key consists of two foreign keys coming from each of the corresponding tables.

I need to find a way to set the relations between the tables in the right way. This is really driving me nuts !!!!!!

Cheers

P