C连接oracle数据库

int db_conn_main()
{

EXEC SQL BEGEIN DECLARE SECTION;
+];
+];
+];

varchar username[];
varchar password[];
varchar connstr[];
EXEC SQL END DECLARE SECTION;

memset(Dbname,0x00,sizeof(Dbname));
if(null=(char*)getenv("DB_USER_NAME"))
{
printf("can not get DB_USER_NAME");
;
}
strcpy(Dbname,(char*)getenv("DB_USER_NAME"));
strcpy((char *)username.arr,Dbname);
username.len=strlen((char *)username.arr);

memset(sDbPWD,0x00,sizeof(sDbPWD));
if(null=(char*)getenv("DB_USER_PASSWORD"))
{
printf("can not get DB_USER_PASSWORD");
;
}
strcpy(sDbPWD,(char*)getenv("DB_USER_PASSWORD"));
strcpy((char *)password.arr,sDbPWD);
password.len=strlen((char *)password.arr);

if(null=(char *)getenv("DB_CONNCET_STRING"))
{
printf("can not get DB_CONNCET_STRING");
;
}
strcpy(sDbSTRING,(char*)getenv("DB_CONNCET_STRING"));
strcpy((char *)connstr.arr,sDbSTRING);
connstr.len=strlen((char *)connstr.arr);

EXEC SQL CONNECT :username IDENTIFIED BY :password USING ;connstr;
if (sqlca.sqlcode != 0) {  printf("连接数据库失败,sqlcode=%d\n", sqlca.sqlcode);  return 4; }
printf("getenv('ORACLE_SID') sucess ");

}