On 2017/12/22 11:06 AM, Radovan Antloga wrote:
I'm using sqlite from version 2. I have 1000+
sql-s written already. I understand that
outermost statement must have AS clause as I
have explained below (select d as d ...).
Sqlite authors always say that new version can
not break sql-s for milions of users using
sqlite. But this change does.
It didn't break for millions of users, it only broke for the few who
relied on behaviour that is documented to not be reliable and that might
change in future.
Usually the Dev team is not in the habit of going around messing with
features just because it is documented as unspecified, but in this case,
it had to change to fix another real bug that had real-world problematic
implications.
Sorry but I did not ask how can I fix my sql-s.
I know I can create table and insert into.
Change select to select d as d is just ridiculous.
Rename column name into same name. What is that?
The first "d" tells SQLite where to find or how to evaluate the value,
the second "d" tells SQLite how to name the output of that SELECT. It
isn't any more ridiculous than SELECT (P+3) AS 'P+3' would be ridiculous.
This is not English101, this is Programming. Rules are rules, even silly
ones.
.../and later/...
>If I have long name then I would have
>select some_long_name_to_understand_column as
some_long_name_to_understand_column
>and if I have 20 columns like that. Just ridiculous or what.
>So once again I use AS clause but why I must use AS clause in
>outer statement if name is already defined in inner select.
Why would you use such a long silly name in the inner query KNOWING that
it is ignored (wrt. to output naming anyway)? That doesn't make a sound
argument.
The CREATE TABLE Evaluates the select with some special considerations
(as documented), nothing prescribes the resulting column name except the
final outer statement's AS clause (as documented). Internally sqlite
doesn't even see Aliases, it has numbers for columns. The outer select
is however the boss, when it says "this-column" AS 'this_name' then
sqlite (and any other DB engine) /has/ to abide by that (as
documented). The aliasing in the inner queries matter none other than
to allow reliable reference pointing between query levels (as documented).
If it were undocumented behaviour you'd still not have a case but some
anger would be understandable, however, you've explicitly relied on
/documented-to-be-non-reliable/ behaviour, I still feel your pain, but
it still isn't a bug and calling it "ridiculous" still won't change that.
(Btw. - the devs might change the behaviour again, maybe even to your
liking if they feel merit and it doesn't break another behaviour, the
point remains that it must not be trusted until it becomes the
documented behaviour.)
I sincerely hope not too many of those 1000+ sql-s need fixing...
Good luck!
Ryan
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