[
https://issues.apache.org/jira/browse/JDO-721?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Michael Bouschen updated JDO-721:
---------------------------------
Attachment: JDO-721.patch
Attached you find a patch JDO-721.patch which adds two new query test cases and
adapts the expected output of some other query tests, because of the new
MedicalInsurance instance having a null field.
I propose the following spec changes:
- Chapter 14.3 Architecture: Query on page page 166:
ordering specification. The ordering specification includes a list of
expressions with the ascending/descending indicator and an optional null
position specification.
- Chapter 14.4 Namespaces in queries on page 167:
Add the following to the list of JDOQL keywords: nulls, NULLS, first, FIRST,
last, LAST
- Chapter 14.6.6 Ordering statement on page 186:
followed by one of the following words: “ascending”, “descending”,“asc”, or
“desc”, followed by an optional null position specification.
The Paragraph "The ordering of instances ... contain non-null values." is
replaced by "The optional null position specification consists of either nulls
first or nulls last. If nulls first is specified, instances containing
null-valued fields are orderd before instances whose fields contain non-null
values. If nulls last is specified, instances containing null-valued fields are
orderd after instances whose fields contain non-null values. Without a null
position the ordering of null values is not specified.
- Chapter B.8 Ordering Specification on page 375:
OrderingSpec:
Expression Ascending NullPositionopt <- opt subscripted
Expression Descending NullPositionopt <- opt subscripted
NullPosition:
nulls first <- bold
nulls last <- bold
- Chapter B.14 Keywords on page 379:
Add the following keywords: nulls, NULLS, first, FIRST, last, LAST
> Specifying NULL elements positioning in ordered columns
> -------------------------------------------------------
>
> Key: JDO-721
> URL: https://issues.apache.org/jira/browse/JDO-721
> Project: JDO
> Issue Type: Improvement
> Components: specification
> Affects Versions: JDO 3 update 1 (3.0.1)
> Reporter: Muhammad Gelbana
> Assignee: Michael Bouschen
> Priority: Minor
> Labels: jdoql
> Fix For: JDO 3.1
>
> Attachments: JDO-721.patch
>
>
> I don't know about other RDBMS but in MySQL ordering, it's possible to
> specify whether NULL column fields are placed in the beginning or at the end
> of the ordering, i.e.:
> ORDER BY `values_column` IS NULL DESC
> [values_column]
> NULL
> NULL
> value1
> value2
> value3
> or the other way around (ORDER BY `values_column` IS NULL ASC):
> [values_column]
> value1
> value2
> value3
> NULL
> NULL
> I checked JDO 3 specification and found that JDOQL's ordering specification
> doesn't support specifying NULL values handling:
> ------------------------------------------------------------------------------
> 26.7 Ordering Specification
> This section describes the syntax of the setOrdering argument.
> OrderingClause:
> OrderingSpecs ,opt
> OrderingSpecs:
> OrderingSpec
> OrderingSpecs , OrderingSpec
> OrderingSpec:
> Expression Ascending
> Expression Descending
> Ascending: one of
> asc ascending
> Descending: one of
> desc descending
> Please note, as a usability feature OrderingClause supports an optional
> trailing comma.
> ------------------------------------------------------------------------------
> Thank you for your time and efforts.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
