there are several examples in the proc directory under
ORACLE_HOME. Whether to use a C program or a shell script is
entirely dependent on what you want to do, and how you will use
the program. If it is something really simple, you might want
to go with the shell script. With a C program, you can do most
anything that you can do with Oracle.
Here is one sample from the oracle documentation at
technet.oracle.com:
/*
- sample1.pc
*
- Prompts the user for an employee number,
- then queries the emp table for the employee's
- name, salary and commission. Uses indicator
- variables (in an indicator struct) to determine
- if the commission is NULL.
*
*/
#include <stdio.h>
#include <string.h>
/* Define constants for VARCHAR lengths. */
#define UNAME_LEN 20
#define PWD_LEN 40
/* Declare variables. No declare section is
needed if MODE=ORACLE. */
VARCHAR username[UNAME_LEN]; /* VARCHAR is an Oracle-
supplied struct */
varchar password[PWD_LEN]; /* varchar can be in lower
case also. */
/* Define a host structure for the output values of
a SELECT statement. */
struct
{
VARCHAR emp_name[UNAME_LEN];
float salary;
float commission;
} emprec;
/* Define an indicator struct to correspond
to the host output struct. */
struct
{
short emp_name_ind;
short sal_ind;
short comm_ind;
} emprec_ind;
/* Input host variable. */
int emp_number;
int total_queried;
/* Include the SQL Communications Area.
You can use #include or EXEC SQL INCLUDE. */
#include <sqlca.h>
/* Declare error handling function. */
void sql_error();
main()
{
char temp_char[32];
/* Connect to ORACLE--
- Copy the username into the VARCHAR.
*/
strncpy((char *) username.arr, "SCOTT", UNAME_LEN);
/* Set the length component of the VARCHAR. */
username.len = strlen((char *) username.arr);
/* Copy the password. */
strncpy((char *) password.arr, "TIGER", PWD_LEN);
password.len = strlen((char *) password.arr);
/* Register sql_error() as the error handler. */
EXEC SQL WHENEVER SQLERROR DO sql_error("ORACLE error--
\n");
/* Connect to ORACLE. Program will call sql_error()
- if an error occurs when connecting to the default database.
*/
EXEC SQL CONNECT :username IDENTIFIED BY :password;
printf("\nConnected to ORACLE as user: %s\n",
username.arr);
/* Loop, selecting individual employee's results */
total_queried = 0;
for (;;)
{
/* Break out of the inner loop when a
- 1403 ("No data found") condition occurs.
*/
EXEC SQL WHENEVER NOT FOUND DO break;
for (;;)
{
emp_number = 0;
printf("\nEnter employee number (0 to quit): ");
gets(temp_char);
emp_number = atoi(temp_char);
if (emp_number == 0)
break;
EXEC SQL SELECT ename, sal, comm
INTO :emprec INDICATOR :emprec_ind
FROM EMP
WHERE EMPNO = :emp_number;
/* Print data. */
printf("\n\nEmployee\tSalary\t\tCommission\n");
printf("--------\t------\t\t----------\n");
/* Null-terminate the output string data. */
emprec.emp_name.arr[emprec.emp_name.len] = '\0';
printf("%-8s\t%6.2f\t\t",
emprec.emp_name.arr, emprec.salary);
if (emprec_ind.comm_ind == -1)
printf("NULL\n");
else
printf("%6.2f\n", emprec.commission);
total_queried++;
} /* end inner for (;;) */
if (emp_number == 0) break;
printf("\nNot a valid employee number - try again.\n");
} /* end outer for(;;) */
printf("\n\nTotal rows returned was %d.\n", total_queried);
printf("\nG'day.\n\n\n");
/* Disconnect from ORACLE. */
EXEC SQL COMMIT WORK RELEASE;
exit(0);
}
void
sql_error(msg)
char *msg;
{
char err_msg[128];
int buf_len, msg_len;
EXEC SQL WHENEVER SQLERROR CONTINUE;
printf("\n%s\n", msg);
buf_len = sizeof (err_msg);
sqlglm(err_msg, &buf_len, &msg_len);
printf("%.*s\n", msg_len, err_msg);
EXEC SQL ROLLBACK RELEASE;
exit(1);
}
> Hi:
> I have to connect to an Oracle Database from a C program...
Could anyone
> help me finding a pattern program for such a connection.
> Would a shell script be more appropriate (I should not use
any Perl
> actually).
> Thanks,
> Edouard
>
>
>
>
--
This answer is courtesy of QuestionExchange.com
http://www.questionexchange.com/showUsenetGuest.jhtml?ans_id=3483&cus_id=USENET&qtn_id=3394
Received on Tue Sep 21 1999 - 07:50:16 CDT
