Re: [sqlite] group_concat(distinct) with empty strings
http://www.sqlite.org/src/info/0deac8737545a020d344be96fff16660a7977ab8 -- D. Richard Hipp d...@sqlite.org ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] group_concat(distinct) with empty strings
Hinrichsen, John wrote:
> Are the results below expected?
> sqlite> SELECT (SELECT GROUP_CONCAT(DISTINCT COALESCE(a,'')) FROM z) IS NULL;
> 1
You don't need DISTINCT:
sqlite> select typeof(group_concat(''));
null
The documentation says:
| The group_concat() function returns a string which is the
| concatenation of all non-NULL values of X.
So this is a bug.
(AFAICS groupConcatStep() does not bother to do anything for empty
strings, so those are handled as if they had been NULL.)
Regards,
Clemens
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[sqlite] group_concat(distinct) with empty strings
Are the results below expected? $ sqlite3 SQLite version 3.8.4.3 2014-04-03 16:53:12 Enter ".help" for usage hints. Connected to a transient in-memory database. Use ".open FILENAME" to reopen on a persistent database. sqlite> CREATE TABLE z AS SELECT NULL AS a; sqlite> SELECT (SELECT DISTINCT COALESCE(a,'') FROM z) IS NULL; 0 sqlite> SELECT (SELECT GROUP_CONCAT(DISTINCT COALESCE(a,'')) FROM z) IS NULL; 1 sqlite> SELECT (SELECT GROUP_CONCAT(DISTINCT COALESCE(a,' ')) FROM z) IS NULL; 0 sqlite> This problem looks similar to: http://sqlite.1065341.n5.nabble.com/group-concat-and-empty-strings-td62226.html -- This message contains confidential information and is intended only for the individual named. If you are not the named addressee, you should not disseminate, distribute, alter or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmissions cannot be guaranteed to be secure or without error as information could be intercepted, corrupted, lost, destroyed, or arrive late or incomplete. The sender, therefore, does not accept liability for any errors or omissions in the contents of this message which arise during or as a result of e-mail transmission. If verification is required, please request a hard-copy version. This message is provided for information purposes and should not be construed as a solicitation or offer to buy or sell any securities or related financial instruments in any jurisdiction. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] group_concat + distinct
afaik "group_concat(distinct a, ',')" is not allowed. "group_concat(distinct a)" or "group_concat(a, ',')" do work. It is mentioned somewhere in the docs. Jan Am 22.09.2010 14:00, schrieb Wiktor Adamski: > SQLite version 3.7.2 > Enter ".help" for instructions > Enter SQL statements terminated with a ";" > sqlite> create table t(a); > sqlite> select group_concat(distinct a) from t; > > sqlite> select group_concat(distinct a, ',') from t; > Error: DISTINCT aggregates must have exactly one argument > > Both queries should return the same result. > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] group_concat + distinct
SQLite version 3.7.2 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> create table t(a); sqlite> select group_concat(distinct a) from t; sqlite> select group_concat(distinct a, ',') from t; Error: DISTINCT aggregates must have exactly one argument Both queries should return the same result. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
