Subject Re[2]: [Firebird-Java] Re: JDBC
Author Nickolay Samofatov
Hello, Robert,

> Nickolay,

> How do you navigate through data if JDBC does not support cursor position?
> How would someone move first, previous, last and next?

JDBC 2.0 spec and later supports cursor positioning. Jaybird doesn't
support this feature yet. Support for this feature in Firebird core is
not tested yet (mainly because there are not too many users
that really need it).

>> >> Can anyone tell me if JDBC for Firebird will allow cursor positioning
>> >> yet?
>>
>> > No, because server does not support this.
>>
>> >> If not, how do you navigate the data?
>>
>> > You don't. SQL is about manipulating a data sets. If we take the idea
>> > to the extreem, ORDER BY should be disabled, because it breaks the
>> > concept. :) SQL client executes a query and fetches the set of data
>> > back to the client. There you can do with data everything you like:
>> > scroll, sort, etc.
>>
>> > This is not convenient for some applications and scrollable cursors
>> > would be of great help. Unfortunatelly server does not provide this
>> > functionality. Delphi users have libraries that emulate such
>> > functionality on the client side, but nobody implemented this for JDBC
>> > yet.
>>
>>I can send you the Firebird 1.6 binary with SCROLLABLE_CURSORS enabled
>>for testing. I have no idea how it performs and if it is deadlock
>>prone, but you can test it. I may try to stabilize this feature if you
>>create JDBC scrollable cursors layer and add testcases for it.


Nickolay Samofatov