Database

SELECT a1.id, b1.amount1, b1.amount2, b1.amount3, 
       a2.id, b2.amount1, b2.amount2, b2.amount3
FROM a a1,
     b b1,
     a a2,
     b b2
WHERE a1.id   = 'x'
AND   b1.a_id = a1.id
AND   a2.id   = 'y'
AND   b2.a_id = a2.id

table 'a' is dynamic can insert or delete id
than i can not create static query (like the sample that you show me)
the data can be like this
a    id
      x
      y
      z

b   id        amount1         amount2           amount3           a_id
    1          5                  3                     5                     x
    1          2                  4                     5                     y
    1          7                  8                     9                     z
    2          3                  1                     3                     x
    2          4                  5                     6                     y
    2          8                  3                     1                     z

result is:

x        5                  3                     5        y         2                  4                     5         z       7                  8                     9    --> id = 1 in table b
x        3                  1                     3        y         4                  5                     6         z       8                  3                     1    --> id = 2 in table b

select * from INFORMATION_SCHEMA.TABLE_CONSTRAINTS where Table_Name = 'TestTable'
 and Constraint_Type = 'FOREIGN KEY'

public class Class1
{


   public DataTable GetData()
   {
      int Code;

      String strCon = "blablablablablablabla";

      SqlConnection con = new SqlConnection(strCon);

      SqlCommand cmdselect = new SqlCommand();

      cmdselect.CommandType = CommandType.StoredProcedure;

      cmdselect.CommandText = "student_SelectAll";

      cmdselect.Connection = con;

      DataTable DT = new DataTable();


      try
      {
          con.Open();

          DT = cmdselect.ExecuteNonQuery();

      }
       catch(SqlException)
      {
           throw;
      }
       finally
      {
          con.Close();
      }

      return DT;

   }

  }

Class1 obj = new Class1();

          DataTable DT = new DataTable();

           DT =  obj.GetData();

           txtname.Text = DT.Columns[0];

           txtlastname.Text = DT.Columns[1];
           //and bla bla blabla