Key

AllowDuplicateKeys

Gets or sets if a duplicate key is possible in the source.

context.BulkMerge(list,options => {
				options.ColumnPrimaryKeyExpression = customer => customer.Name;
				options.AllowDuplicateKeys = true;
			});

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AllowUpdatePrimaryKeys

Gets or sets if the key must also be included in columns to UPDATE.

context.BulkSaveChanges(options => options.AllowUpdatePrimaryKeys = true);