db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Mamta A. Satoor (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-3166) Update docs to address code improvments to LIKE (see Derby-2967)
Date Thu, 29 Nov 2007 20:51:43 GMT

    [ https://issues.apache.org/jira/browse/DERBY-3166?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12546882
] 

Mamta A. Satoor commented on DERBY-3166:
----------------------------------------

Laura, thanks for working on this doc item. Looks like the files impacted are cdevcollation.html,
rrefsqli23075.html Let me know if rrefattribupgrade.html and rtuntransform443.html changed
too.

As for cdevcollation.html, rrefsqli23075.html, the changes generally look pretty good. But
I think the statement, "When LIKE comparisons are used with territory-based collation, Derby
compares one character at a time for non-metacharacters. This is different than the way Derby
processes = comparisons.", might sound like LIKE is handled differently for UCS_BASIC and
terriotry based databases. For both kinds of databases, SQL specification requires us to do
LIKE comparison one character at a time. This is not a biggie with UCS_BASIC because the unicode
values for the entire string will be same as unicode value for individual characters in that
string taken in the given sequence. But for territory based database, the collation elements
returned for an entire string may not be same as individual collation element(s) one character
at a time in that string in the given sequence. I hope this is not too confusing but what
I am saying is one character at a time comparison for LIKE is not unique to territory based
databases. May be rephrasing the sentence above as "When LIKE comparisons are used, Derby
compares one character at a time for non-metacharacters. This is different than the way Derby
processes = comparisons"

Another minor comment for cdevcollation.html, section Differences between LIKE and equal (=)
comparisons. The first sentence should say When you use territory-based collation, the comparisons
*can* return different results when you use the LIKE and equal (=) operators.

> Update docs to address code improvments to LIKE (see Derby-2967)
> ----------------------------------------------------------------
>
>                 Key: DERBY-3166
>                 URL: https://issues.apache.org/jira/browse/DERBY-3166
>             Project: Derby
>          Issue Type: Bug
>          Components: Documentation
>            Reporter: Laura Stewart
>            Assignee: Laura Stewart
>         Attachments: cdevcollation.html, derby3166._1.diff, rrefattribupgrade.html, rrefsqlj23075.html,
rtuntransform443.html
>
>
> Implement the required doc changes for collation to address the improvements to the LIKE
operator.

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


Mime
View raw message