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MergeFailed Event
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DataSet.MergeFailed Event

Occurs when a target and source DataRow have the same primary key value, and EnforceConstraints is set to true.

Namespace:  System.Data
Assembly:  System.Data (in System.Data.dll)

public event MergeFailedEventHandler MergeFailed

For more information about handling events, see Consuming Events.

The following example demonstrates the use of the MergeFailed event.

    private static void DemonstrateMergeFailedEvent()
        // Create a DataSet with one table containing two columns.
        DataSet dataSet = new DataSet("dataSet");
        DataTable table = new DataTable("Items");
        // Add table to the DataSet.

        // Add two columns to the DataTable.
        table.Columns.Add("id", typeof(int));
        table.Columns.Add("item", typeof(int));

        // Set the primary key to the first column.
        table.PrimaryKey = new DataColumn[] { table.Columns["id"] };

        // Add MergeFailed event handler for the table.
        dataSet.MergeFailed += new MergeFailedEventHandler(Merge_Failed);

        // Create a second DataTable identical to the first, 
        DataTable t2 = table.Clone();

        // Set the primary key of the new table to the second column. 
        // This will cause the MergeFailed event to be raised when the 
        // table is merged into the DataSet.
        t2.PrimaryKey = new DataColumn[] { t2.Columns["item"] };
        // Merge the table into the DataSet.
        dataSet.Merge(t2, false, MissingSchemaAction.Add);

    private static void Merge_Failed(object sender, MergeFailedEventArgs e)
        Console.WriteLine("Merge_Failed Event: '{0}'", e.Conflict);

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0
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