Manage

The manage step provides data management functionality for your application and/or process.

Below is the code for Manage():

/*

 * Manage()

 *

 * This function performs simple record functions of add, delete and gets

 */

void Manage(void)

{

   os_printf(DH_STRING_LITERAL("MANAGE\n"));

   /* delete any existing records */

   Delete_Records();

   /* populate the table with data */

   Add_CustomerMaster_Records();

   /* display contents of table */

   Display_Records();

   /* update a record under locking control */

   Update_CustomerMaster_Record();

   /* display again after update and effects of lock */

   Display_Records();

}

/*

 * Delete_Records()

 *

 * This function deletes all the records in the table

 */

void Delete_Records(void)

{

   os_printf(DH_STRING_LITERAL("\tDelete records...\n"));

   EXEC SQL DELETE FROM custmast ;

   if (sqlca.sqlcode < 0)

      Handle_Error(sqlca.sqlcode, sqlca.sqlerrm);

   EXEC SQL COMMIT WORK ;

}

/*

 * Add_CustomerMaster_Records()

 *

 * This function adds records to table CustomerMaster from an

 * array of strings

 */

void Add_CustomerMaster_Records(void)

{

EXEC SQL BEGIN DECLARE SECTION ;

   char  sCommand[512];

EXEC SQL END DECLARE SECTION ;

   dh_char_t	*data[] = {

      DH_STRING_LITERAL("('1000','92867','CA','1','Bryan Williams','2999 Regency','Orange')"),

      DH_STRING_LITERAL("('1001','61434','CT','1','Michael Jordan','13 Main','Harford')"),

      DH_STRING_LITERAL("('1002','73677','GA','1','Joshua Brown','4356 Cambridge','Atlanta')"),

      DH_STRING_LITERAL("('1003','10034','MO','1','Keyon Dooling','19771 Park Avenue','Columbia')")

   };

   int		i;

   int		nRecords = sizeof(data) / sizeof(data[0]);

   Delete_Records();

   os_printf(DH_STRING_LITERAL("\tAdd records...\n"));

   /* add one record at time to table */

   for (i = 0; i < nRecords; i++)

   {

      os_sprintf (sCommand, DH_STRING_LITERAL("INSERT INTO custmast VALUES %s"), data[i]);

      EXEC SQL EXECUTE IMMEDIATE :sCommand ;

      if (sqlca.sqlcode)

         Handle_Error(sqlca.sqlcode, sqlca.sqlerrm);

   }

   EXEC SQL COMMIT WORK;

}

/*

 * Display_Records()

 *

 * This function displays the contents of a table.

 */

void Display_Records(void)

{

   EXEC SQL BEGIN DECLARE SECTION ;

   CHAR  custnumb[5+1];

   CHAR  custname[47+1];

   EXEC SQL END DECLARE SECTION ;

   os_printf(DH_STRING_LITERAL("\tDisplay records..."));

   EXEC SQL DECLARE curs CURSOR FOR

      SELECT custmast.cm_custnumb, custmast.cm_custname FROM custmast;

   if (sqlca.sqlcode)

      Handle_Error(sqlca.sqlcode, sqlca.sqlerrm);

   EXEC SQL OPEN curs;

   if (sqlca.sqlcode)

      Handle_Error(sqlca.sqlcode, sqlca.sqlerrm);

   EXEC SQL FETCH curs INTO :custnumb, :custname;

   /* fetch and display each individual record */

   while (!sqlca.sqlcode)

   {

      os_printf(DH_STRING_LITERAL("\n\t\t%-8s%10s\n"),custnumb, custname);

      EXEC SQL FETCH curs INTO :custnumb, :custname;

   }

   EXEC SQL CLOSE curs ;

}

/*

 * Update_CustomerMaster_Records()

 *

 * Update one record under locking control to demonstrate the effects

 * of locking

 */

void Update_CustomerMaster_Record(void)

{

   os_printf(DH_STRING_LITERAL("\tUpdate record...\n"));

   EXEC SQL UPDATE custmast SET cm_custname = 'KEYON DOOLING' WHERE cm_custnumb = '1003';

   if (sqlca.sqlcode)

      Handle_Error(sqlca.sqlcode, sqlca.sqlerrm);

   os_printf(DH_STRING_LITERAL("\tPress <ENTER> key to unlock\n"));

   getchar();

   EXEC SQL COMMIT WORK;

}