This exception is thrown when you attempt to invoke the DataRowCollection.Contains( ) or DataRowCollection.Find( ) method on a DataTable that has no primary key. To retrieve primary key information, you can use the IDataAdapter.FillSchema( ) method when accessing a data source. To programmatically set a primary key, you must add a UniqueConstraint (typically by setting the DataColumn.Unique property of the primary key field to true ) and then set the UniqueConstraint.IsPrimaryKey property to true .

public class MissingPrimaryKeyException : DataException {
// Public Constructors
   public MissingPrimaryKeyException(  );  
   public MissingPrimaryKeyException( string s);  
// Protected Constructors
   protected MissingPrimaryKeyException(System.Runtime.Serialization.SerializationInfo info,
        System.Runtime.Serialization.StreamingContext context);
}

Hierarchy

System.Object System.Exception(System.Runtime.Serialization.ISerializable) System.SystemException DataException MissingPrimaryKeyException