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14.6 AcceptChangesDuringFillThe AcceptChangesDuringFill( ) controls whether AcceptChanges( ) is implicitly called on new rows when they are added to a DataTable by the Fill( ) method. If AcceptChangesDuringFill is true, the rows added as a result of the Fill( ) have a RowState of Unchanged after they are added to the DataSet. If AcceptChangesDuringFill is false, the RowState of the newly added rows is Added. The following example demonstrates this: // connection and select command strings String connString = "Data Source=(local);Integrated security=SSPI;" + "Initial Catalog=Northwind;"; String selectSql = "SELECT * FROM Orders"; // create a new DataSet to receive the data DataSet ds = new DataSet(); SqlDataAdapter da = new SqlDataAdapter(selectSql, connString); da.Fill(ds, "Orders"); // each row in the Orders table has RowState = Unchanged ds.Tables["Orders"].Clear(); da.AcceptChangesDuringFill = false; da.Fill(ds, "Orders"); // each row in the Orders table has RowState = Inserted // manually call AcceptChanges ds.AcceptChanges(); // each row in the Orders table has RowState = Unchanged The default value for AcceptChangesDuringFill is true. Because the records already exist in the data source, the records retrieved during the Fill( ) operation should not be considered new records when the data source is eventually updated with the DataSet. Setting AcceptChangesDuringFill to false can be useful, for example, to transfer data between data sources. Records retrieved from a data source are marked as New, and the DataSet can then insert these records into another data source using the Update( ) method of a DataAdapter. |
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