DataSet.MergeFailed Event

Definition

Namespace:

System.Data

Assemblies:

netstandard.dll, System.Data.Common.dll

Source:

DataSet.cs

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

C#

public event System.Data.MergeFailedEventHandler? MergeFailed;

Event Type

MergeFailedEventHandler

Examples

The following example demonstrates the use of the MergeFailed event.

C#

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.
    dataSet.Tables.Add(table);

    // 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.
    Console.WriteLine("Merging...");
    dataSet.Merge(t2, false, MissingSchemaAction.Add);
}

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

Remarks

For more information about how to handle events, see Handling and Raising Events.

Applies to

See also

• Using DataSets in ADO.NET