[jira] Updated: (DERBY-3975) SELECT DISTINCT may return duplicates with territory-based collation

["Knut Anders Hatlen (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/DERBY-3975?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Knut Anders Hatlen updated DERBY-3975:
--------------------------------------

    Attachment: AisBCollatorProvider.java

Here's the CollatorProvider I used to define the locale. To use it, do the following:

$ mkdir -p META-INF/services
$ javac AisBCollatorProvider.java
$ echo AisBCollatorProvider > META-INF/services/java.text.spi.CollatorProvider
$ jar cf aisb-collator.jar AisBCollatorProvider.class META-INF
$ java -Djava.ext.dirs=. -jar /path/to/derbyrun.jar ij

> SELECT DISTINCT may return duplicates with territory-based collation
> --------------------------------------------------------------------
>
>                 Key: DERBY-3975
>                 URL: https://issues.apache.org/jira/browse/DERBY-3975
>             Project: Derby
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 10.4.2.0
>            Reporter: Knut Anders Hatlen
>         Attachments: AisBCollatorProvider.java
>
>
> I defined my own locale (en_US_aisb) where the collation rules said that a=b. When I tried queries with SELECT DISTINCT, they didn't always eliminate all duplicates. Here's an example:
> ij> connect 'jdbc:derby:db;create=true;territory=en_US_aisb;collation=TERRITORY_BASED';
> ij> create table t (x varchar(10));
> 0 rows inserted/updated/deleted
> ij> insert into t values 'a','b','abba','baab','ABBA';
> 5 rows inserted/updated/deleted
> ij> select distinct * from t;
> X         
> ----------
> ABBA      
> b         
> a         
> abba      
> 4 rows selected
> ij> select distinct * from t order by x;
> X         
> ----------
> a         
> abba      
> ABBA      
> 3 rows selected
> The first query did eliminate the duplicate "abba"/"baab", but it did not eliminate the duplicate "a"/"b". When an ORDER BY clause was added (the second query), all the duplicates were eliminated.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.