How can I evaluate the count of a query I'd like to execute with a map...

Question

Hi. I have a problem with a query...
I hava created a query which a execute with a Map (I use the
executeWithMap(Map) method). The problem is that sometimes this query
returns a large resultset. So, I would like to execute an other query
(called query_count) before executing ther final query with the Map. If
the query_count returns a count < 200, I execute the final query. How can
I do ? There is an example I have read this in the documentation :
Query query = pm.newQuery (Magazine.class, "price < 5");
query.setResult ("count(this)");
Long count = (Long) query.execute ();
The problem in this example is that the query is not execute with a Map.
So my question is : "How can we do the evalute the count of a query we
would like to execute with a map ?". Thank you for any response.

Answer 1

Hi John,
You should be able to executeWithMap that query, too. Is that giving you
problems?
Note that there may be an easier solution. What do you do if there are more
than 200 results? If, e.g., you just get the first N, then one option is to
set the FetchBatchSize on the query to N (thus activating large result set
support), and then call size () on the resulting Collection. This will
issue a SELECT COUNT(*) to the database to determine the size automatically.
Thanks,
Greg
"John" <[email protected]> wrote in message
news:ctq9a8$4gr$[email protected]..
>
Hi. I have a problem with a query...
I hava created a query which a execute with a Map (I use the
executeWithMap(Map) method). The problem is that sometimes this query
returns a large resultset. So, I would like to execute an other query
(called query_count) before executing ther final query with the Map. If
the query_count returns a count < 200, I execute the final query. How can
I do ? There is an example I have read this in the documentation :
Query query = pm.newQuery (Magazine.class, "price < 5");
query.setResult ("count(this)");
Long count = (Long) query.execute ();
The problem in this example is that the query is not execute with a Map.
So my question is : "How can we do the evalute the count of a query we
would like to execute with a map ?". Thank you for any response.