Re: how to assert into the db with rdbms

Thomas Russ <[email protected]> wrote:
> 
> On May 18, 2007, at 8:29 AM, Kambiz Darabi wrote:
>
>> But, how can I assert facts into the database?
>
> This part of our database functionality is not yet completed.
> We are having some technical difficulties with proper handling of
> Function assertions.
>
> If you only use concepts and relations, we have something
> experimental that works, but it isn't released, not even in the new
> snapshots.
>

As I understand, powerloom is in use in projects with very large
knowledge bases. Did you create the databases separately (using other
DB interfaces) and just did the reasoning in PL?

I would like to use PL to derive new facts from assertions which are
entered into the system. PL would then be a semantic layer on top of
the RDBMS, which would be capable of checking and augmenting the
information on the way to the database.

Is such a use feasible with the current capabilities of PL?

Is there a chance of getting the part which allows to assert concepts
and relations?

>>
>> Another problem is: I can use defquery to define queries involving one
>> single table, but I don't manage to define sql table joins correctly.
>>
>> [...]
>>
>> 2) defquery with an SQL join
>
> Something like this should work:
>
> Assume DB tables
>   employees:  employeeName  employeeDepartment
>   departments:  department  managerName
>
> (DEFQUERY employeeBoss ((?employeeName STRING) (?bossName STRING))
>   :QUERY-PATTERN
>   (RDBMS/SQL-QUERY our-db
>      "SELECT employeeName, managerName FROM employees, departments
> WHERE #${employeeName='?employeeName'}
> AND #${managerName='?managerName'}
> AND employeeDepartment = department
> "))
>
> What are you trying that is failing?


Given this:

create table parents (id integer, name varchar(255));
create table child (id integer, parentid integer, name varchar(255));
insert into parents values (1, 'John');
insert into child values (1, 1, 'Kevin');
insert into child values (2, 1, 'Mary');

what would be the query pattern for:

(DEFQUERY parent-child ((?parentid integer) (?parentname STRING) (?childname STRING))
   ...

?


Thanks a lot for your kind assistance!


Kambiz