JDOQL Correlated Subquery - Bad SQL

Question

Hi,
When I execute a JDOQL correlated subquery, the generated SQL is either
invalid or incorrect. Exactly what happens depends on the exact query, and
on the target database type, but I believe it all stems from the same
problem, which has to do with table aliasing.
If you need further details to reproduce this, please let me know. I'll be
glad to help in any way I can to get this situation remedied quickly, as I
am depending on this functionality. I have a test application to
demonstrate the problem.
I'm using Kodo 3.3.3 and application identity.
Paul Mogren
CommerceHub

Answer 1

For the record, this is in part due to a bug in Kodo's SQL92 joining.
See http://bugzilla.solarmetric.com/show_bug.cgi?id=1156
-Patrick
Paul Mogren wrote:
Certainly... Here's a simple example using Microsoft's JDBC Driver for SQL
Server 2000, and kodo.jdbc.sql.SQLServerDictionary, which produces invalid
SQL.
The query:
pm.newQuery(Container.class,
"(select from Entry entry where entries.contains(entry) &&
entry.containedId != 1).isEmpty()");
The classes:
class Contained {
private int id; //pk
class Container {
private int id; //pk
private Set entries = new HashSet(); //<Entry>
class Entry {
private int containerId; //pk
private int containedId; //pk
private Container container; //persistent-redundant
private Contained contained; //persistent-redundant
The result:
Incorrect syntax near the keyword 'WHERE'. {prepstmnt 31598780 SELECT
t0.container_id, t0.lock FROM  WHERE (NOT EXISTS (SELECT DISTINCT
t2.contained_id, t2.container_id FROM dbo.entry t2 WHERE (t1.contained_id
= t2.contained_id AND t1.container_id = t2.container_id AND
t2.contained_id <> ?) AND t0.container_id = t1.container_id))
[params=(int) 1]} [code=156, state=HY000]
Patrick Linskey wrote:
Hi Paul,
Kodo's correlated subquery support does have some known limitations. Can
you post a sample JDOQL statement + corresponding SQL statement?
-Patrick
Paul Mogren wrote:
Hi,
When I execute a JDOQL correlated subquery, the generated SQL is either
invalid or incorrect. Exactly what happens depends on the exact query, and
on the target database type, but I believe it all stems from the same
problem, which has to do with table aliasing.
If you need further details to reproduce this, please let me know. I'll be
glad to help in any way I can to get this situation remedied quickly, as I
am depending on this functionality. I have a test application to
demonstrate the problem.
I'm using Kodo 3.3.3 and application identity.
Paul Mogren
CommerceHub