[Zope] OQL for ZODB - (SQL like for objects Databases)

[Kapil Thangavelu]

Its probably possible but its probably more work than you're interested
in. 

They speak different languages a relational system is built on relations
in square/rectangular tables. an object system esp. the ZODB can store
objects which can be of arbitrary nature, not to mention acquistion and
inheritance.

a couple of pointers (maybe misleading)

what you need is an object relational mapping that understands the ZODB
and SQL.

it depends on what you want to do with it and what kind of queries

looking at your original email, this sounds most like you just want...
ie to be able to retrieve objects based on properties in which case
ZCatalog is the way to go. A Catalog is an object indexing system built
on top of the ZODB for maintaining knowledge of objects and they're
properties for fast searching/retrieval. if you really want an sql
syntax to the ZODB read on but be warned getting at acquired props will
require some serious work/design.

you could create an inherited catalog that can layer a simple sql syntax
over its searches and design it to return objects instead of references.

you could also write a custom ORB that could map into the ZODB according
to SQL syntax. 

although i haven't looked at the source. chris m's Interbase storage
might be worth a look (it probably stores everything as a BLOB which
might not be helpful).

Other systems that might be helpful are OZONE an open source java OODBMS
and Lore an XML storage with searches.

Kapil
 
E. Discors wrote
> 
> Hi,
> Is there a tool like SQL for ZODB ?
> Where to find more to do some query on ZODB objects ?
> 
> Many Thanks.
> Emmanuel.
> 
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