Re: ~How to use RAW and LONG RAW columns ?

From: Vladimir Pasechnik <vpas_at_unisoft.dp.ua>
Date: 25 Jun 1998 20:53:34 +0300
Message-ID: <AB6sdary0G_at_unisoft.dp.ua>

RC> Hey Y'all,
RC>
RC> I'm trying to store BINARY files in a LONG RAW column (such as BITMAPs,
RC> DOC files, WAVs etc), but none of my reference books tell me HOW to
RC> actually do it.
RC>
RC> I'm using Pro*C with Oracle 7.2 (so I can't use BLOBs !!)
RC>
RC> Got any ideas ???
RC>
RC>
RC> Thanks,
RC> Richard
RC>
RC> email: richard_at_rockdb.demon.co.uk

  Hi, Richard.
  In Pro*C 2.x you can work with LONG RAW columns, using expression    EXEC SQL TYPE <your_structure> IS long varraw (MAX_FILE_SIZE);

   where <your_structure> is

   typedef struct { long len; char buf[MAX_FILE_SIZE]; } <your_structure>;

   Example from sample going with the Pro*C 2.x documentation:

#include <sqlca.h>
#include <string.h>
#include <stdio.h>
#include <io.h>

#define DISCARD (void)
#define S2VCPY(vch,s) \

    DISCARD strcpy((char *)vch.arr,s);\
    vch.len = (unsigned short) strlen(s)
#define VCHNULL(v) v.arr[v.len] = '\0'
   EXEC SQL BEGIN DECLARE SECTION;
#define MAX_FILE_SIZE 500000

   typedef struct { long len; char buf[MAX_FILE_SIZE]; } long_varraw;    EXEC SQL END DECLARE SECTION;
   EXEC SQL TYPE long_varraw IS long varraw (MAX_FILE_SIZE);

   int insert(char *key,char *file)
   {
    EXEC SQL BEGIN DECLARE SECTION;
    long_varraw lvr1;
    VARCHAR key1[20];
    EXEC SQL END DECLARE SECTION;
    EXEC SQL DECLARE db_name DATABASE;

    printf("Inserting file %s under key %s...\n", file, key);     S2VCPY(key1,key);
    lvr1.len = read_file(file, lvr1.buf, MAX_FILE_SIZE);     if (lvr1.len == -1)
    { fprintf(stderr,"\n\nError while reading file ô%sô:\n", file);

      EXEC SQL AT db_name ROLLBACK WORK RELEASE;
      return(1);

    }

    EXEC SQL WHENEVER SQLERROR DO sql_error("insert");     EXEC SQL AT db_name INSERT INTO executables (name, binary)     VALUES (:key1, :lvr1);
    EXEC SQL AT db_name COMMIT;
    printf("Inserted.\n");
}

int read_file(char *filename,char *buf,long bufsize) {

#define LOCAL_BUFFERSIZE 512

   char local_buffer[LOCAL_BUFFERSIZE];
   FILE *stream;
   int number_read,in_fd,total_size=0;

   if ((stream=fopen( filename, "rb" ))==NULL)    { printf("Can't open file %s for read\n",filename); return(-2);}    in_fd=_fileno(stream);
   while ((number_read = _read(in_fd, local_buffer,

                                 LOCAL_BUFFERSIZE)) > 0)
   {
     if (total_size + number_read > bufsize)
         { close(in_fd); return(-1); }
         memcpy(buf+total_size, local_buffer, number_read);
     total_size += number_read;

   }
   _close(in_fd);
   return(total_size);
}

  I hope it will help.

  WBR,
      Vlad

  UniSoft,ltd
  Dniepropetrovsk
  Ukraine Received on Thu Jun 25 1998 - 19:53:34 CEST