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updating dataset

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Robin

In a .Net solution that has a DAL, Class and Business logic.
When recreating a dataset from the class the records are inserted into the
database from the dataset instead of updating. This is using the dataset
merge command.

Is there any settings that should be used to ensure that the data is
updating instead of inserted?

Reply to this message...

Saurabh Nandu (VIP)

Hi,

I am not too sure if this works, but here's what i feel is the problem.

DataAdapter.Update works based on the RowState of the DataRow.

So a DataRowState.Added will lead to the record being inserted into the
database, while a DataRowState.Modified will lead to the record being updated
in the database.

Now the RowState property of the DataRow within a DataTable is read-only.
But the only way to modify it is to first add the row in the DataTable in you
class and then modify its values.

ie
(from MSDN)

private void DemonstrateRowState() {
//Run a function to create a DataTable with one column.
DataTable myTable = MakeTable();
DataRow myRow;

// Create a new DataRow.
myRow = myTable.NewRow();
// Detached row.
Console.WriteLine("New Row " + myRow.RowState);

myTable.Rows.Add(myRow);
// New row.
Console.WriteLine("AddRow " + myRow.RowState);

myRow["FirstName"] = "Scott";
// Modified row.
// After Modification the Row should now Update to the Database
Console.WriteLine("Modified " + myRow.RowState);

}

private DataTable MakeTable(){
// Make a simple table with one column.
DataTable dt = new DataTable("myTable");
DataColumn dcFirstName = new DataColumn("FirstName",
Type.GetType("System.String"));
dt.Columns.Add(dcFirstName);
return dt;
}

Regards,
Saurabh Nandu
[ www.AksTech.com ]
[ www.MasterCSharp.com ]

"Robin" wrote:

[Original message clipped]

Reply to this message...

	System.Console
	System.Data.Common.DataAdapter
	System.Data.DataColumn
	System.Data.DataRow
	System.Data.DataRowState
	System.Data.DataTable
	System.String
	System.Type

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