Re: Windows Ada database support.

[Frank Piron <empty@zero.nil>]

Fri, 26 Nov 2004 10:15:06 +0100 Dmitry A. Kazakov 
<mailbox@dmitry-kazakov.de> wrote:

> And more importantly why that crappy SQL over and over again? I would 
> like
> to see a high level Ada.Database[.Relational?] package totally 
> independent
> on what happens beneath.
>
But what language for querying and manipulating data would you
suggest?
IMO it should

- be declarative
- boolean closed
- allow restricted quantification

Some LQL (Logical query language based on Predicate Calculus)
would be nice.
Example: (Database for Genealogical data)

Base Predicates(Tables): Person(x,s), Parent(x,y)     |(s = sex)
Show all Fathers:

LQL:
Father(x):=E(y)[Person(x,s) and
                 s='MALE'    and
                 Parent(x,y)
                 ]

SQL:
select Person.x
      from Person, Parent
       where Person.s='MALE' and
             Person.x = Parent.x   (inner join for the E-Quantifier)

Similar to Prolog.

Other implementations would use only persistent types and their methods
in a distributed environment (like Cachￜ).

-- 
Frank Piron,
defrankatkonaddot
(leftrotate two)