Dennis wrote:

> Deal all.
>
> I want to ask the base with a query and to return me if there is a least on
> record with specific criteria.
>
> Using select code_a from sales where partno='2323' the firebird computes all
> the records where are going to be transferred to the client.
>
> Is there any way to reduce this time, so the firebird will answer, yes there
> is one record with these criteria.

try WHERE EXISTS

>
> Note: To make it clear, I am working with the ibx7 and I am talking with the
> database relationally, so there is no case to transfer all the query's
> results to client directly
>
> For instance, I want to list all customers where they have movements: So the
> query I developed is the follow:
>
> select * from customers
>
> where
>
> (select count(*) from reg_header where customer_code='23232323') > 0

WHERE EXISTS (SELECT * FROM reg_header WHERE customer_code = 23232323')

>
> order by name
>

regards
ian