C#

private static void OMEGA_calcActvEqv()
  {
      SqlConnection conn1 = CommonFunctions.getSQLConnectionForThread(THREAD_DATA[0].ToString());
      string SQL = "SELECT MAX(D.OFFS + 1) * MAX(R.OFFS + 1) FROM TBL_ROWS R, TBL_CLMN D; SELECT MAX(OFFS + 1) FROM TBL_ROWS;";
      SqlCommand cmd = new SqlCommand(SQL, conn1);
      SqlDataReader rdr = cmd.ExecuteReader();

      int size = 0;
      if (rdr.Read())
      {
          size = Convert.ToInt32(rdr[0]);
      }

      int maxPeriods = 0;
      if (rdr.NextResult())
      {
          if (rdr.Read())
          {
              maxPeriods = Convert.ToInt32(rdr[0]);
          }
      }
      rdr.Close();

      SQL = "SELECT MEA.EQV [EQV], MEA.ACTV [ACTV] FROM MTM_EQV_ACTV MEA ORDER BY MEA.EQV, MEA.ACTV ";

      if ((THREAD_DATA.Length > 3) && (THREAD_DATA[3] != null))
      {
          string EQV = CommonFunctions.ExecuteScalarInThread("SELECT MEA.EQV FROM MTM_EQV_ACTV MEA WHERE ACTV=" + THREAD_DATA[3], conn1).ToString();
          SQL = "SELECT MEA.EQV [EQV], MEA.ACTV [ACTV] FROM MTM_EQV_ACTV MEA WHERE EQV='" + EQV + "' ORDER BY MEA.EQV, MEA.ACTV ";
      }

      cmd = new SqlCommand(SQL, conn1);
      rdr = cmd.ExecuteReader();

      string eqvSet = string.Empty;
      List<int> actvs = new List<int>();

      while (rdr.Read())
      {
          if (eqvSet != rdr["EQV"].ToString())
          {
              if (actvs.Count > 1)
              {
                  OMEGA_intersectDomns(actvs, size, maxPeriods);
              }

              actvs.Clear();
              eqvSet = rdr["EQV"].ToString();
              if (!DBNull.Value.Equals(rdr["ACTV"]))
              {
                  actvs.Add(Convert.ToInt32(rdr["ACTV"]));
              }
          }
          else
          {
              if (!DBNull.Value.Equals(rdr["ACTV"]))
              {
                  actvs.Add(Convert.ToInt32(rdr["ACTV"]));
              }
          }
      }

      rdr.Close();

      if (actvs.Count > 1)
      {
          OMEGA_intersectDomns(actvs, size, maxPeriods);
          actvs.Clear();
      }

      conn1.Close();
      conn1.Dispose();
  }

public static object ExecuteScalarInThread(string sql, SqlConnection conn1)
{

    SqlCommand sqlcommand = new SqlCommand(sql, conn1);
    //You need to apply the the connection to the command after connection open
    sqlcommand.CommandType = CommandType.Text;

    object ret = new object();

    if (conn1.State != ConnectionState.Open)
    {
        conn1.Open();
    }
    try
    {
        ret = sqlcommand.ExecuteScalar();
    }
    catch (Exception e)
    {
        ret = e.Message;
    }

    conn1.Close();
    return ret;
}

rdr = cmd.ExecuteReader();

ExecuteReader requires an open and available Connection. The connection's current state is closed.