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 they exist. Otherwise create and open the table

 */

#ifdef PROTOTYPE

VOID Define(VOID)

#else

VOID Define()

#endif

{

   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

 */

#ifdef PROTOTYPE

VOID Create_CustomerMaster_Table(VOID)

#else

VOID Create_CustomerMaster_Table()

#endif

{

   CTHANDLE pField1, pField2, pField3, pField4;

   CTHANDLE pField5, pField6, pField7;

   CTHANDLE pIndex;

   CTHANDLE pIseg;

   /* define table CustomerMaster */

   printf("\ttable CustomerMaster\n");

   /* allocate a table handle */

   if ((hTable = ctdbAllocTable(hDatabase)) == NULL)

      Handle_Error("Create_CustomerMaster_Table(): ctdbAllocTable()");

   /* open table */

   if (ctdbOpenTable(hTable, "custmast", CTOPEN_NORMAL))

   {

      /* define table fields */

      pField1 = ctdbAddField(hTable, "cm_custnumb", CT_FSTRING, 4);

      pField2 = ctdbAddField(hTable, "cm_custzipc", CT_FSTRING, 9);

      pField3 = ctdbAddField(hTable, "cm_custstat", CT_FSTRING, 2);

      pField4 = ctdbAddField(hTable, "cm_custratg", CT_FSTRING, 1);

      pField5 = ctdbAddField(hTable, "cm_custname", CT_STRING, 47);

      pField6 = ctdbAddField(hTable, "cm_custaddr", CT_STRING, 47);

      pField7 = ctdbAddField(hTable, "cm_custcity", CT_STRING, 47);

      if (!pField1 || !pField2 || !pField3 || !pField4 ||

          !pField5 || !pField6|| !pField7)

         Handle_Error("Create_CustomerMaster_Table(): ctdbAddField()");

      /* define index */

      pIndex = ctdbAddIndex(hTable, "cm_custnumb_idx", CTINDEX_FIXED, NO, NO);

      pIseg = ctdbAddSegment(pIndex, pField1, CTSEG_SCHSEG);

      if (!pIndex || !pIseg)

         Handle_Error("Create_CustomerMaster_Table(): ctdbAddIndex()|ctdbAddSegment()");

      /* create table */

      if (ctdbCreateTable(hTable, "custmast", CTCREATE_NORMAL))

         Handle_Error("Create_CustomerMaster_Table(): ctdbCreateTable()");

      /* open table */

      if (ctdbOpenTable(hTable, "custmast", CTOPEN_NORMAL))

         Handle_Error("Create_CustomerMaster_Table(): ctdbOpenTable()");

   }

   else

   {

      Check_Table_Mode(hTable);

      /* 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

       */

      if (ctdbGetIndexByName(hTable, "cm_custnumb_idx") == NULL)

      {

         pField1 = ctdbGetFieldByName(hTable, "cm_custnumb");

         pIndex = ctdbAddIndex(hTable, "cm_custnumb_idx", CTINDEX_FIXED, NO, NO);

         pIseg = ctdbAddSegment(pIndex, pField1, CTSEG_SCHSEG);

         if (!pIndex || !pIseg)

            Handle_Error("Create_CustomerMaster_Table(): ctdbAddIndex()|ctdbAddSegment()");

         if (ctdbAlterTable(hTable, CTDB_ALTER_NORMAL) != CTDBRET_OK)

            Handle_Error("Create_CustomerMaster_Table(): ctdbAlterTable()");

      }

   }

}

/*

 * 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

 */

#ifdef PROTOTYPE

VOID Check_Table_Mode(CTHANDLE hTable)

#else

VOID Check_Table_Mode(hTable)

CTHANDLE hTable;

#endif

{

   CTCREATE_MODE mode;

   /* get table create mode */

   mode = ctdbGetTableCreateMode(hTable);

   /* check if table is under transaction processing control */

   if ((mode & CTCREATE_TRNLOG))

   {

      /* change file mode to disable transaction processing */

      mode ^= CTCREATE_TRNLOG;

      if (ctdbUpdateCreateMode(hTable, mode) != CTDBRET_OK)

         Handle_Error("Check_Table_Mode(); ctdbUpdateCreateMode");

   }

}