史上最简单元的pro*c程序

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
EXEC SQL include sqlca;
EXEC ORACLE OPTION (RELEASE_CURSOR = YES);
EXEC SQL BEGIN DECLARE SECTION;
                VARCHAR username[20];
                VARCHAR password[20];
EXEC SQL END DECLARE SECTION;
void sql_error()
{
                EXEC SQL WHENEVER SQLERROR CONTINUE;
                printf("\n Oracle error detected:\n");
                printf("\n%.70s\n",sqlca.sqlerrm.sqlerrmc);
                EXEC SQL ROLLBACK RELEASE;
exit(1);
}
main()
{
                strcpy(username.arr,"gdnum_true");
                strcpy(password.arr,"gdnumtrue_10");
                username.len=strlen(username.arr);
                password.len=strlen(password.arr);
                EXEC SQL CONNECT :username IDENTIFIED BY :password;
                prin