Re: Support for CALL statement in ecpg

Hello.

At Thu, 18 Jul 2019 16:38:54 +0530, Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote in <CAE9k0PkKCsbZLurU5O5V3+c1F-ANKFoKpzpMUa6LQFP9+dcJFA(at)mail(dot)gmail(dot)com>
> Hi All,
>
> In the current code for ecpg, we can't use CALL statement to call
> stored procedures. The attached patch adds the support for it.
>
> With the attached patch, we can now have the following SQL statement
> in ecpg application to call the stored procedures with IN or INOUT
> params.
>
> EXEC SQL CALL SP1(:hv1, :hv2);
>
> Additionally, we can also use indicator variables along with the
> arguments of stored procedure with CALL statement like shown below:
>
> EXEC SQL CALL SP1(:hv1 :ind1, :hv2, :ind2);
>
> The patch also adds some basic test-cases to verify if CALL statement
> in ecpg can be used to call stored procedures with different type of
> parameters.
>
> Please have a look and let me know your thoughts.
>
> Thank you.

+ECPG: CallStmtCALLfunc_application

Even though it is the default behavior, but as a written rule
this needs the postfix "block".

+ $$ = cat_str(2,mm_strdup("call"),$2);

Let's have proper spacing.

+ * Copy input arguments to the result arguments list so that all the
+ * host variables gets treated as INOUT params.

This fails for the following usage:

-- define procedure
create procedure ptest2 (in x int, inout y int) language plpgsql as $$
begin
y := y + x;
end;
$$;

-- in .pgc
14: a = 3;
15: r = 5;
16: EXEC SQL call ptest2(:a, :r);
21: printf("ret = %d, %d\n", a, r);

This complains like this:

> SQL error: too many arguments on line 16
> ret = 8, 5;

The result should be "3, 8". This is because the patch requests
two return but actually retruned just one.

I'm not sure how to know that previously on ecpg. Might need to
let users append INTO <vars> clause explicitly.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center