Re: Pro*C/C++ and the goto operator
Date: Tue, 05 Oct 1999 05:42:09 GMT
Message-ID: <7tc33g$a3o$1_at_nnrp1.deja.com>
Thank you very much for your answer.
I am starting to use Oracle8 (including Pro*c/C++),
so sometimes I have got questions.
In article <37F8E53D.AA60F032_at_Unforgettable.com>,
BlueSax_at_Unforgettable.com wrote:
> Why do you want to write something that goes against the standards
that
> Oracle has instituted?
- I would like to use only standards.
- I don't use goto-operator in C/C++.
- So, I am trying to find another operator in Pro*C/C++ that
- does not go against standard
- is eqivalent to GOTO operator.
> If you follow Oracle's method of using Pro-C your
> code will be highly portable and maintainable.
>
> There is an alternative to the goto. You could write something to the
> effect of:
>
> EXEC SQL WHENEVER NOT FOUND DO myfunc();
>
> If you do it that way, if a fetch causes a 1403 then myfunc() will be
> called, but that may not give you the desired result.
Why may result be undesirable?
[Quoted] (We don't need goto-operator in C/C++. Do we have to use this operator in Pro*C/C++?)
>
> Hint: look at the precompiler output to see what happens to the EXEC
SQL
> syntax when it is rewritten into executible statements by the
precompiler.
EXEC SQL suntax and corresponding executible statements
are shown below (see Appendix).
But I don't find the answer on my question.
>
> Ken
>
[snip]
Thanks in advance, Alex
Appendix.
- GOTO operator ===============
- EXEC SQL syntax -----------
- (sample1.pc) -----------
for (;;)
{
[--- omitted ---]
/* Branch to the notfound label when the
* 1403 ("No data found") condition occurs.
*/
EXEC SQL WHENEVER NOT FOUND GOTO notfound;
[--- omitted ---]
continue;
notfound:
printf("\nNot a valid employee number - try again.\n");
} /* end for(;;) */
- executible statements -----
- (sample1.c) ------------
for (;;)
{
[--- omitted ---]
/* Branch to the notfound label when the
* 1403 ("No data found") condition occurs.
*/
/* EXEC SQL WHENEVER NOT FOUND GOTO notfound; */
[--- omitted ---]
{
struct sqlexd sqlstm;
[--- omitted ---]
if (sqlca.sqlcode == 1403) goto notfound;
if (sqlca.sqlcode < 0) sql_error("ORACLE
error--\n");
}
[--- omitted ---]
continue;
notfound:
printf("\nNot a valid employee number - try again.\n");
} /* end for(;;) */
=============================================
=============== DO operator =================
- EXEC SQL syntax -----------
- (sample1.pc) -----------
/* Declare error handling function. */
void sql_error(msg)
char *msg;
{
char err_msg[128];
size_t 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(EXIT_FAILURE);
} /* void sql_error(msg) */
void main()
{
[--- omitted ---]
/* Register sql_error() as the error handler. */
EXEC SQL WHENEVER SQLERROR DO sql_error("ORACLE error--\n");
[--- omitted ---]
} /* void main() */
- executible statements -----
- (sample1.c) ------------
/* Declare error handling function. */
void sql_error(msg)
char *msg;
{
char err_msg[128];
size_t 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; */
{
struct sqlexd sqlstm;
sqlstm.sqlvsn = 10;
sqlstm.arrsiz = 0;
sqlstm.sqladtp = &sqladt;
sqlstm.sqltdsp = &sqltds;
sqlstm.iters = (unsigned int )1;
sqlstm.offset = (unsigned int )5;
sqlstm.cud = sqlcud0;
sqlstm.sqlest = (unsigned char *)&sqlca;
sqlstm.sqlety = (unsigned short)0;
sqlcxt((void **)0, &sqlctx, &sqlstm, &sqlfpn);
}
exit(EXIT_FAILURE);
} /* void sql_error(msg) */
void main()
{
[--- omitted ---]
/* Register sql_error() as the error handler. */
/* EXEC SQL WHENEVER SQLERROR DO sql_error("ORACLE error--\n");
*/
[--- omitted ---]
{
struct sqlexd sqlstm;
[--- omitted ---]
if (sqlca.sqlcode < 0) sql_error("ORACLE error--\n");
}
[--- omitted ---]
} /* void main() */
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Received on Tue Oct 05 1999 - 07:42:09 CEST