[V4MD] link types

[Ruslan Zasukhin]

On 5/29/05 8:07 PM, "Peter Salomon" <peter.salomon at gmx.net> wrote:

Hi Peter,

> i have not understood well the function of automatically generated
> link when i create an objectPtr field.

> Are there differences between a link created by e.g. binary link and
> this link type?

Yes this is not the same.

In Valentina 2.0 exists 3 kinds of links between table:

1) Foreign Key -- come to us from Relational model
        people used to RDBMS as mySQL, Oracle, MS
        know this good

    it works as LINK BY VALUE.


2) ObjectPtr -- come to us from Valentina 1.x
        this is a field in the MANY table.
           
    it works as DIRECT POINTER.
        

3) BinaryLink -- totally new kind of link.
        any DBMS do not have it.

    it works as ... Additional third M : M table.
    but without that table.

BinaryLink can handle M : M links,
FK and ObjectPtr only M : 1


-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]