Re: nothing ever works

Hi Everyone,

Firstly I would like to thank everyone for your feedback. Secondly I would
like to apologise, I had spent some time trying to write some dynamic SQL
in postgres yesterday and got extremely frustrated at the the time I
wasted. I realize this a community and I'm sorry for not being more
constructive in my comment.

The reason for my frustration is this has happened before; where I look the
examples and think I know how to use it only to run into syntax errors. I
have tried the specific dynamic SQL examples inside script blocks and I get
syntax errors. If it only works in functions it would be good to know that.

If it's not that then I wonder if perhaps the problem is PG Admin.

Often the way I learn with a new language is by trying to do something that
I need. Hence I hit the docs at the point that I think will help me. If
this happens with other developers perhaps it would be helpful for the
examples to list where the specific language feature can be used.

I am not the only one as my colleagues have run into exactly the same thing.

Hopefully this input is a little more constructive and again thank you all
for taking the time to respond.

On Thu, 22 Jun 2017 at 02:47 David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>
wrote:

> >>> 2017-06-21 10:39 GMT+02:00 <gerardmatt(at)gmail(dot)com>:
> >>>
> >>> Your documentation although it seems straight forward actually never
> >>> works.
>
> Most of it is not written as self-contained examples so this is not
> surprising.
>
> >>> Please explain limitations or where the script can actually be
> executed.
>
> That would be the responsibility of chapters 36 and 41.2 (and maybe
> some others); chapters prior to the one you are complaining about.
> Again, this isn't a cookbook format where every section and example is
> self-contained. This requires the reader to adopt their own
> techniques for actually starting with functioning code and keeping it
> functioning as new capabilities are introduced. For better and worse
> I don't foresee any volunteering significant time to change the style
> of the documentation - particularly without a large volume of specific
> complaints and/or suggestions to work from.
>
> >>> As a beginner starting out in postgre you can never rely on the
> >>> documentation because the same thing happens, you copy the code and
> make
> >>> your modifications and you get syntax error.
>
> Which means that some more fundamental aspect of the capability you
> are trying to learn hasn't yet been figured out and so that code you
> are writing is not operating in the context that the documentation
> assumes it is. You need to go back earlier in the
> process/documentation and get the fundamentals out of the way.
>
> >>> Clearly define the limitations of your language so that developers
> >>> don&#39;t
> >>> waste their time.
>
> Either there is a distinct lack of others encountering the same
> problems or they avail themselves of other solutions. In any case the
> authors of the documentation cannot foresee every confusion or problem
> that may arise. That's part of why the mailing lists exist. Ideally
> you'd come here, get un-stumped, look back at why you got stumped in
> the first place, and suggest documentation improvements that would
> help prevent the next person from being stumped in a similar matter.
> That flow would, IMO, be in the true spirit of this open source
> community.
>
> >>> Coming from ms sql quite frankly I would never recommend postgress. The
> >>> barrior to entry into actualy writing code is too great.
>
> --file: create-functions.sql
> --might not work as-is but the structural components you require are here.
> CREATE FUNCTION remove_all_users() RETURNS SETOF bigint AS $$
> DELETE FROM users RETURNING user_id;
> $$ LANGUAGE SQL;
>
> CREATE FUNCTION do_it() RETURNS void AS $$
> BEGIN
> RAISE NOTICE 'Performing User Removal';
> PERFORM remove_all_users(); -- using perform since we don't care about
> returned user_id's
> END;
> $$ LANGUAGE plpgsql;
>
> $psql
> >\i create-functions.sql
> #now the two functions exist on the server
> >SELECT do_it();
> %NOTICE: Performing User Removal
> do_it
> -------
>
> --this would be roughly equivalent but "DO" won't return a result
> which SELECT do_it() does.
> --still in psql...
> DO $$
> BEGIN
> PERFORM remove_all_users();
> END;
> $$; --implied pl/pgsql language
>
> I cannot speak to learning MS SQL compared to PostgreSQL; but in some
> ways having existing, but difference, experience hurts since you are
> apt to make assumptions about how things should work that are not
> true.
>
> Your welcome to your venting but all I see here is a specific case of
> learning having gone into spiral. The community here is great at
> helping people get themselves out these kinds of spirals. That the
> documentation cannot do so all by itself is not a failing of the
> documentation or its authors.
>
> David J.
>