The XDb2 script listed below creates a 2kg dog named fido and a 2.2kg
cat named miffy. Each mass (2kg and 2.2kg) has a quantity (2 and 2.2)
and units (kg). In addition, the quantities (2 and 2.2) are typed as
integer or float in the db. See www.xdb2.com/Example/Ex110.asp for
details.

// Create necessary classes
CREATE2 *mass.cls = thing;
CREATE2 *qty.cls = thing;
CREATE2 *unit.cls = thing;
CREATE2 *type.cls = thing;

// Create qty 2 and type it as an integer
CREATE2 *;
CREATE2 it.name = +'2';
CREATE2 it.cls = qty;
CREATE2 it.type = +integer;

// Create qty 2.2 and type it as a float
CREATE2 *;
CREATE2 it.name = +'2.2';
CREATE2 it.cls = qty;
CREATE2 it.type = +float;

// Create mass 2kg
CREATE2 *;
CREATE2 it.cls = mass;
CREATE2 it.qty = (%.cls=qty & %.name='2');
CREATE2 it.unit = +kg;

// Create mass 2.2kg
CREATE2 *;
CREATE2 it.cls = mass;
CREATE2 it.qty = (%.cls=qty & %.name='2.2');
CREATE2 it.unit = +kg;

// Create a dog named fido and set his mass to 2kg
CREATE2 *dog.cls = thing;
CREATE2 *fido.cls = dog;
CREATE2 fido.mass = (%.cls=mass & %.qty=2 & %.unit=kg);

// Create a cat named miffy and set her mass to 2kg
CREATE2 *cat.cls = thing;
CREATE2 *miffy.cls = cat;
CREATE2 miffy.mass = (%.cls=mass & %.qty=2.2 & %.unit=kg);

// Query to find things whose mass is in units of kg
// Finds fido and miffy
SELECT2 %.mass=(%.cls=mass & %.unit=kg);

// Query to find mass instances whose qty is typed as float
// Finds 2.2 kg
SELECT2 %.cls=mass & %.qty=(%.type=float);

neo55592 (AT) hotmail (DOT) com (Neo) wrote:

I sure wish I could create a dog and cat out of nothing. OK,
maybe not. I am not allowed to have pets in my apartment.

[snip]

Sincerely,

Gene Wirchenko

Computerese Irregular Verb Conjugation:
I have preferences.
You have biases.
He/She has prejudices.

Please show how to represent/query the equivalent (or similar) things
using your preferred methodology (ie RM, Objects, Haskell, C++, Third
Manifesto, Tutorial D, etc)?

"Neo" <neo55592 (AT) hotmail (DOT) com> wrote


The above message is both redundant and NULL.

It's redundant because it's about the hundredth time you've started a
message with "Please show how".

It's NULL because it is content free.

On Sat, 6 Nov 2004 14:51:31 -0500, "Laconic2" <laconic2 (AT) comcast (DOT) net>
wrote:

Just like it's author.

Lemming
--
Curiosity *may* have killed Schrodinger's cat.