API methods + binary link + M:M tables

[Ruslan Zasukhin]

On 1/31/05 4:22 PM, "Olivier" <vidal_olivier at yahoo.fr> wrote:

> Hi Ruslan,
> 
> I try to think only in navigationnal way to use the API methods.
> But in the following problem, I do not see how I can have an effective
> API code:
> 
> 
> I shall like knowing how much there is of persons having the same
> surname in every city. (Statistics).
> 
> For example:
> 
> PARIS:
> 
> Name   Counts
> 
> name1  500
> name2   300
> name3   100
> 
> (thus, there 100 persons at Paris having the surname "name3")
> 
> BORDEAUX:
> 
> name1  300
> name2  150
> name3   80
> 
> ..............
> 
> I think thus of having:
> 
> - A city table (there are 36 000 cities)
> - A table of surnames (several thousand surnames)
> - A table (tbQuantity) making the link between the previous two tables
> AND having a field: "counts" ("counts"=Number of persons having this
> surname in a city)

I do not think you need COUNTS table.

I see only reason to have it, if you prepare some DB for CD and you want
optimize of for speed as much as possible.

If you develop regular db that will change runtime then I think this will
make things more complex then needed.

 
> - A binary link 1:M between the table "quantity" and the table "name"
> - A binary link 1:M between the table "quantity" and the table "city"

No no no. 

All should be natural and mirror the real world entities.

> I think that it is necessary to make the third table (quantity) because
> of this field "counts".
> 
> It is not maybe a good structure to use the API methods, but in that
> case, can we better make?
> 
> Apparently, the best solution here are join them and SQL?

Aha! Look into ValentinaSQL.pdf

Here exists new group of "Link Methods".
It seems to me you need the function

    COUNT( link_name, fld_B )

But I am not sure...


-----------------
Aha! Guys!

I think we need yet extend syntax of GROUP BY in the SQL to support Binary
Link. Because now there is no way to say
    
    GROUP records of PERSON that are linked to some CITY

With ObjectPtr-link field we can do this grouping by ObjectPtr itself.
With binaryLink there is no such ability.
So we must have syntax as

    Select 
    From
    GROUP BY link_name

Sergey, Ivan, you see idea?


-- 
Best regards,
Ruslan Zasukhin      [ I feel the need...the need for speed ]
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e-mail: ruslan at paradigmasoft.com
web: http://www.paradigmasoft.com

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