SQL overall is phenomenally ambiguous about group-by:
1) select a0 + 1 as a0 from a group by a0
has a different behaviour in different SQL implementations, depending on
whether the group-by prefers the underlying column or the projection alias.
2) As you rightly point out, group by integer has a different behaviour
in different implementations, depending on how they range-check for "is
a projection reference" - is a valid integer, is out of range, ...
3) group by expression has several of the above ambiguities, when it's
legal.
4) Everything else is AFU'd too.
S.
On 05/31/2018 09:49 AM, Mark Brand wrote:
At first I wasn't sure what you meant by "column identifier". It's what
the documentation calls "column-alias". But this also qualifies as an
"other expression" doesn't it? A column alias can appear pretty much
anywhere any expression can, except in the same column list where it is
defined.
Mark
On 31/05/18 18:27, Hick Gunter wrote:
Ponder the following select fragment
SELECT name, year * 100 + month as period, day + hour / 24.0 from
some_table
Then you can have
ORDER BY 1,2,3 -- integer output column numbers
which is equivalent to
ORDER BY name, period, day + hour / 24.0 -- output column identifier
x2 + "any other expression"
-----Original Message-----
From: sqlite-users
[mailto:sqlite-users-boun...@mailinglists.sqlite.org] On Behalf Of
Mark Brand
Sent: Mittwoch, 30. Mai 2018 16:22
To: sqlite-users@mailinglists.sqlite.org
Subject: Re: [sqlite] [EXTERNAL] unexpected error with "GROUP BY 0"
Thanks for the clarification.
You have constant integers, output column identifiers and "any other
expression" as terms for GROUP BY.
Just to make sure I'm not missing something subtle: I understand the
"constant integer" is what gets interpreted as a result column number.
What is an "output column identifier" then? Isn't it already covered
by the broader category "any other expression"?
It's still a pretty astonishing language feature(!?) that an integer
numeric-literal, which in every other column-like context represents
its integer value, gets interpreted after GROUP BY or ORDER BY as a
result column number. Fortunately, SQLite isn't to blame for designing
this.
By the way, this feature is documented for ORDER BY, but I don't see
it for GROUP BY.
Mark
On 30/05/18 13:28, Hick Gunter wrote:
You have constant integers, output column identifiers and "any other
expression" as terms for GROUP BY. If the expression evalutes to a
constant value, you will have only one output row.
-----Ursprüngliche Nachricht-----
Von: sqlite-users
[mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im Auftrag von
Mark Brand
Gesendet: Mittwoch, 30. Mai 2018 12:11
An: sqlite-users@mailinglists.sqlite.org
Betreff: Re: [sqlite] [EXTERNAL] unexpected error with "GROUP BY 0"
Thanks. I had forgotten that GROUP BY considers a literal integer in
this context to be a column number, a feature I don't use.
These, on the other hand, work as I would have expected:
sqlite> select 0 group by cast (0 as int);
0
sqlite> select 0 group by (select 0);
0
Mark
On 30/05/18 12:00, Hick Gunter wrote:
Yes. If the expression is a constant integer K, then it is
considered an alias for the K-th column of the result set. Columns
are ordered from left to right starting with 1.
There is no 0-th column, so GROUP BY 0 is "out of range", just the
same as "SELECT 0 GROUP BY 31" would be.
-----Ursprüngliche Nachricht-----
Von: sqlite-users
[mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im Auftrag von
Mark Brand
Gesendet: Mittwoch, 30. Mai 2018 11:32
An: SQLite mailing list <sqlite-users@mailinglists.sqlite.org>
Betreff: [EXTERNAL] [sqlite] unexpected error with "GROUP BY 0"
Hi,
Is there a good reason for this error:
sqlite> SELECT 0 GROUP BY 0;
Error: 1st GROUP BY term out of range - should be between 1 and 1
sqlite> SELECT 0 GROUP BY 1;
0
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0430013 | (O) +43 1 80100 - 0
May be privileged. May be confidential. Please delete if not the
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GmbH | Klitschgasse 2-4, A-1130 Vienna | FN 157284 a, HG Wien, DVR:
0430013 | (O) +43 1 80100 - 0
May be privileged. May be confidential. Please delete if not the
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