Re: How to do the equivalent of 'describe' with a SELECT?

On 31 Mar 2007 07:50:06 -0700, "Ramon F Herrera" <ramon_at_conexus.net> wrote:

>
>The SQL code that I need is for a Pro*C/C++ application. Before my
>compiled C program does its main thing, it should check the current
>sizes of the variables in the target table.
>

Why, do you think you can dynamically change the change of variables of a *compiled* program? That would be very weird.

>I would like to be able to change the variables' sizes, for instance,
>from:
>
>VARCHAR(20);
>
>to
>
>VARCHAR(30);
>
>without having to recompile all my C programs. Or at least, reduce the
>impact of such resize.
>
>TIA,
>
>-Ramon

In PL/SQL you would declare the variable as

<variable> <table>.<column>%type

but you would still need to recompile everything (automagically). May be something similar exists in Pro*C. Apart from that your task is impossible: you simply can't change dynamically the limits of *statically* declared variables, or you would need pointer variables everywhere. Such is the fate of a developer hardcoding everything and not using constants.

-- 



Sybrand Bakker
Senior Oracle DBA