Re: Help! Pro*C (under unix) and LONG data columns!
Date: 1995/12/01
Message-ID: <49lgl7$pnc_at_inet-nntp-gw-1.us.oracle.com>
Steve,
At the bottom you will find a sample proc app that
creates a table
creates a 100k blob in memory
inserts it into the table
commits
selects is back out to verify it
drops the table
It shows you one way to interface with longs in the database. I have it set up to do long RAWS, you would change the LONG VARRAW(100000) reference to LONG VARCHAR(100000) reference for longs.
slarocque_at_southam.ca (Steve LaRocque) wrote:
>Does anyone have any examples of reading/modifying and inserting rows in
>tables where one of the fields is a LONG datatype, from within Pro*C?
>Pro*C is v2.0.6, DBMServer is 7.1.2
>*ANY* help would be greatly appreciated. Canadian tech support doesn't
>have anyone with Pro*C experience under Unix (or so they claim)!
>Regards,
>Steve LaRocque
>PS: I'd prefer email to me at slarocque_at_southam.ca or just followup this
>message. Thanks.
>--
>Steve LaRocque
>mailto:slarocque_at_southam.ca
#include <stdio.h> #include <string.h> #include <ctype.h> #include <assert.h>
#define vstrcpy( a, b ) \
(strcpy( a.arr, b ), a.len = strlen( a.arr ), a.arr)
static char * USERID = NULL;
#define SQLCA_INIT
EXEC SQL INCLUDE sqlca;
EXEC SQL BEGIN DECLARE SECTION;
int SQLCODE;
EXEC SQL END DECLARE SECTION;
static void process_parms( argc, argv )
int argc;
char * argv[];
{
int i;
for( i = 1; i < argc; i++ )
{
if ( !strncmp( argv[i], "userid=", 7 ) ) USERID = argv[i]+7;
else
{
printf( "usage: %s userid=xxx/xxx\n", argv[0] );
exit(1);
}
}
if ( USERID == NULL )
{
printf( "usage: %s userid=xxx/xxx\n", argv[0] );
exit(1);
}
}
static void sqlerror_hard()
{
EXEC SQL WHENEVER SQLERROR CONTINUE;
printf("\nORACLE error detected:");
printf("\n% .70s \n", sqlca.sqlerrm.sqlerrmc);
EXEC SQL ROLLBACK WORK RELEASE;
exit(1);
}
static void process()
{
/* * This is the data structure we will use with our LONG RAWs. We will * always use pointers to this structure as we don't know how big we need * until runtime. Will use malloc to allocate storage on the fly. */
typedef struct TAGmy_raw
{
long len; unsigned char arr[1]; } my_raw; /* * Use type equivalencing to tell Oracle that the C type "my_raw" is * equivalent to the Oracle type LONG VARRAW and can hold upto 5k * bytes of data (we will never allocate that much here, just an upper
- bound, could be MUCH higher (eg: 10,000,000) */ EXEC SQL TYPE my_raw IS LONG VARRAW(100000) REFERENCE;
my_raw * buffer;
long size = 100000;
int i;
EXEC SQL WHENEVER SQLERROR DO sqlerror_hard();
printf( "EXEC SQL CREATE TABLE TEST_BLOB ( X LONG RAW );\n" );
EXEC SQL CREATE TABLE TEST_BLOB ( X LONG RAW );
/*
* we will allocate a little over 4k of space
*/
buffer = (my_raw *)malloc( size+sizeof(my_raw) );
/*
* fill it up with every possible byte value from 0..254
*/
for( i = 0; i < size; i++ )
buffer->arr[i] = i % 255;
/*
* Just like a varchar, set the length field
*/
buffer->len = size;
printf( "INSERT INTO TEST_BLOB\n" );
EXEC SQL INSERT INTO TEST_BLOB ( X ) values ( :buffer );
/*
* commit the changes
*/
printf("EXEC SQL COMMIT WORK;\n" );
EXEC SQL COMMIT WORK;
/*
* Now, ZERO out the buffer so when we fetch, we know that the buffer
* was NOT equal to what it was on the insert. Just to *prove* that
* the fetch got back the data we inserted
*/
memset( buffer->arr, 0, size );
/*
* Select out the data
*/
printf( " SELECT X INTO :buffer FROM TEST_BLOB;\n" );
EXEC SQL SELECT X
INTO :buffer
FROM TEST_BLOB;
/*
* show what size we got
*/
printf( "The Length = %ld\n", buffer->len );
/*
* Check each character to make sure it is what we inserted
*/
for( i = 0; i < size; i++ )
if ( buffer->arr[i] != i % 255 )
{
printf( "Error! %d != %d\n", buffer->arr[i], i%255 );
break;
}
/*
* delete that table
*/
printf( "EXEC SQL DROP TABLE TEST_BLOB;\n" );
EXEC SQL DROP TABLE TEST_BLOB;
}
main( argc, argv )
int argc; char * argv[];
{
EXEC SQL BEGIN DECLARE SECTION;
VARCHAR oracleid[50];
EXEC SQL END DECLARE SECTION; process_parms( argc, argv );
/* Connect to ORACLE. */
vstrcpy( oracleid, USERID );
EXEC SQL WHENEVER SQLERROR DO sqlerror_hard();
EXEC SQL CONNECT :oracleid;
printf("\nConnected to ORACLE as user: %s\n\n", oracleid.arr);
process();
/* Disconnect from ORACLE. */
EXEC SQL COMMIT WORK RELEASE;
exit(0);
}
Thomas Kyte
tkyte_at_us.oracle.com
Oracle Government
Received on Fri Dec 01 1995 - 00:00:00 CET