Define

The Define() step is where specific data definitions are established by your application and/or process. This involves defining columns/fields and creating the tables/files with optional indices.

Below is the code for Define():

//

// Define()

//

// Open the table, if it exists. Otherwise create and open the table

//

VOID Define(VOID)

{

   printf("DEFINE\n");

   Create_CustomerMaster_Table();

}

//

// Create_CustomerMaster_Table()

//

// Open table CustomerMaster, if it exists. Otherwise create it

// along with its indices and open it

//

VOID Create_CustomerMaster_Table(VOID)

{

   CTBOOL   do_create = NO;

   // define table CustomerMaster

   printf("\ttable CustomerMaster\n");

   try

   {

      MyTable.Open("custmast", CTOPEN_NORMAL);

   }

   catch (...)

   {

      // table does not exist

      do_create = YES;

   }

   if (do_create)

   {

      try

      {

         // define table fields

         CTField field1 = MyTable.AddField("cm_custnumb", CT_FSTRING, 4);

         MyTable.AddField("cm_custzipc", CT_FSTRING, 9);

         MyTable.AddField("cm_custstat", CT_FSTRING, 2);

         MyTable.AddField("cm_custratg", CT_FSTRING, 1);

         MyTable.AddField("cm_custname", CT_STRING, 47);

         MyTable.AddField("cm_custaddr", CT_STRING, 47);

         MyTable.AddField("cm_custcity", CT_STRING, 47);

         // define index

         CTIndex index1 = MyTable.AddIndex("cm_custnumb_idx", CTINDEX_FIXED, NO, NO);

         index1.AddSegment(field1, CTSEG_SCHSEG);

         // create table

         printf("\tCreate table...\n");

         MyTable.Create("custmast", CTCREATE_NORMAL);

         // open table

         printf("\tOpen table...\n");

         MyTable.Open("custmast", CTOPEN_NORMAL);

      }

      catch (CTException E)

      {

         Handle_Exception(E);

      }

   }

   else

   {

      Check_Table_Mode(MyTable);

      // confirm the index exists, if not then add the index

      //

      // this scenario arises out of the fact that this table was created in tutorial 1

      // without indexes. The index is now created by the call to ctdbAlterTable

      do_create = NO;

      try

      {

         MyTable.GetIndex("cm_custnumb_idx");

      }

      catch (CTException E)

      {

         do_create = YES;

      }

      if (do_create)

      {

         try

         {

            CTField field1 = MyTable.GetField("cm_custnumb");

            CTIndex index1 = MyTable.AddIndex("cm_custnumb_idx", CTINDEX_FIXED, NO, NO);

            index1.AddSegment(field1, CTSEG_SCHSEG);

            MyTable.Alter(CTDB_ALTER_NORMAL);

         }

         catch (CTException E)

         {

            Handle_Exception(E);

         }

      }

   }

}

//

// Check_Table_Mode()

//

// Check if existing table has transaction processing flag enabled.

// If a table is under transaction processing control, modify the

// table mode to disable transaction processing

//

VOID Check_Table_Mode(CTTable& table)

{

   try

   {

      // get table create mode

      CTCREATE_MODE mode = table.GetCreateMode();

      // check if table is under transaction processing control

      if ((mode & CTCREATE_TRNLOG))

      {

         // change file mode to disable transaction processing

         mode ^= CTCREATE_TRNLOG;

         table.UpdateCreateMode(mode);

      }

   }

   catch (CTException E)

   {

      Handle_Exception(E);

   }

}