Best way to use OQL with PB

[Clóvis Wichoski <cl...@uol.com.br>]

Hi,

I'm using PersistenceBroker and need use OQL only for selecting objects, 
then I will use OQLQueryImpl, only to make the Query object for me, but 
I have two issues in doubt:

1) Executing query with broker
...
OQLQueryImpl oql = new OQLQueryImpl(broker.getPBKey());
oql.create(sbOQL.toString());
Collection results = broker.getCollectionByQuery(oql.getQuery());
...

2) Executing query with OQLQueryImpl
...
OQLQueryImpl oql = new OQLQueryImpl(broker.getPBKey());
oql.create(sbOQL.toString());
ManageableCollection results = oql.execute();
...

Then the doubts are:

What is better approach issue 1, issue 2 or exists a better way?

Since I will use the PB for me the best is issue 1, but for future 
compatibility don't be better to have a class QueryByOQL like QueryBySQL 
or QueryByCriteria?

Is correct instancing OQLQueryImpl programmatically?

TIA

Clóvis








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Re: Best way to use OQL with PB

[Thomas Mahler <th...@web.de>]

Hi Clovis,


Clóvis Wichoski wrote:
> Hi,
> 
> I'm using PersistenceBroker and need use OQL only for selecting objects, 
> then I will use OQLQueryImpl, only to make the Query object for me, but 
> I have two issues in doubt:
> 
> 1) Executing query with broker
> ...
> OQLQueryImpl oql = new OQLQueryImpl(broker.getPBKey());
> oql.create(sbOQL.toString());
> Collection results = broker.getCollectionByQuery(oql.getQuery());
> ...
> 
> 2) Executing query with OQLQueryImpl
> ...
> OQLQueryImpl oql = new OQLQueryImpl(broker.getPBKey());
> oql.create(sbOQL.toString());
> ManageableCollection results = oql.execute();
> ...
> 
> Then the doubts are:
> 
> What is better approach issue 1, issue 2 or exists a better way?

1 is faster, as 2 involves creating a dummy ODMG transaction and 
registering all result object to that transaction.
I see no better way to do this.
> 
> Since I will use the PB for me the best is issue 1, but for future 
> compatibility don't be better to have a class QueryByOQL like QueryBySQL 
> or QueryByCriteria?

I guess you are the first one to use oql queries with the PB API. So I 
guess noone had the idea to write a "QueryByOql" class yet.
But, yes, it could be a nice wrapper to your 1) approach.

> 
> Is correct instancing OQLQueryImpl programmatically?

I see no problems,

cheers,
Thomas

> 
> TIA
> 
> Clóvis
> 
> 
> 
> 
> 
> 
> 
> 
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