private void GetConstraints(DataTable dataTable)
   {
       Console.WriteLine();

       // Print the table's name.
       Console.WriteLine("TableName: " + dataTable.TableName);

       // Iterate through the collection and 
       // print each name and type value.
       foreach(Constraint constraint in dataTable.Constraints ) 
       {
           Console.WriteLine("Constraint Name: " 
               + constraint.ConstraintName);
           Console.WriteLine("Type: " 
               + constraint.GetType().ToString());

           // If the constraint is a UniqueConstraint, 
           // print its properties using a function below.
           if(constraint is UniqueConstraint) 
           {
               PrintUniqueConstraintProperties(constraint);
           }
           // If the constraint is a ForeignKeyConstraint, 
           // print its properties using a function below.
           if(constraint is ForeignKeyConstraint) 
           {
               PrintForeigKeyConstraintProperties(constraint);
           }
       }
   }

   private void PrintUniqueConstraintProperties(
       Constraint constraint)
   {
       UniqueConstraint uniqueConstraint;
       uniqueConstraint = (UniqueConstraint) constraint;

       // Get the Columns as an array.
       DataColumn[] columnArray;
       columnArray = uniqueConstraint.Columns;

       // Print each column's name.
       for(int i = 0;i<columnArray.Length ;i++) 
       {
           Console.WriteLine("Column Name: " 
               + columnArray[i].ColumnName);
       }
   }

   private void PrintForeigKeyConstraintProperties(
       Constraint constraint)
   {
       ForeignKeyConstraint fkConstraint;
       fkConstraint = (ForeignKeyConstraint) constraint;

       // Get the Columns as an array.
       DataColumn[] columnArray;
       columnArray = fkConstraint.Columns;

       // Print each column's name.
       for(int i = 0;i<columnArray.Length ;i++) 
       {
           Console.WriteLine("Column Name: " 
               + columnArray[i].ColumnName);
       }
       Console.WriteLine();

       // Get the related columns and print each columns name.
       columnArray = fkConstraint.RelatedColumns ;
       for(int i = 0;i<columnArray.Length ;i++) 
       {
           Console.WriteLine("Related Column Name: " 
               + columnArray[i].ColumnName);
       }
       Console.WriteLine();
   }