Objects from Aliases?

[Former Member]

Hi

I have a question

I have 3 tables(X,Y,Z) connected to a dimension A, and they form a loop.

I have built 2 aliases on A to connect to 2 of these tables and joined one table directly to table Z.

So X is joined to A_X,

Y is joined to A_Y

& Z is joined to A).

I want to know, should I build objects straight out of the Dimension A and have reports built on these objects and objects from X, Y or Z.

These 3 tables have different contexts on each of them and are disjoint tables.

Or should objects be built on aliases only and not the main table.

Thanks

[Former Member]

Hi BOUser,

Once you have created 3 different aliases you must treat them as if they were separate tables.

If you have a column C on Dimension_A, then you will also get a Column_C on A_X and A_Y. However, if you point an object to Dimension_A.C it will not get you A_X.C or A_Y.c

A real world example might help explain it better

Imagine you have an Order, Invoice, Transaction, containing Order_Date, Invoice_Date and Transaction_Date. Each of these point to a Date_Lookup table, which has been aliased as Order_date_lookup, Invoice_Date_Lookup and Transaction_Date lookup. Assuming the Date Lookup columns you want to expore are month, day and year. Then you will need to create 3 classes, one for each lookup with 3 fields.

Class:Order Date

Object:Year,SQL:Order_Date.Year

Object:Month,SQL:Order_Date.Month

Object:Day,SQL:Order_Date.Day

Class:Invoice Date

Object:Year,SQL:Invoice_Date.Year

Object:Month,SQL:Invoice_Date.Month

Object:Day,SQL:Invoice_Date.Day

Class:Transaction Date

Object:Year,SQL:Transaction_Date.Year

Object:Month,SQL:Transaction_Date.Month

Object:Day,SQL:Transaction_Date.Day

So to answer your question, it is really both. It is all about what you want the user to see.

Hope this helps

Alan

[Former Member]

Thanks a lot Alan. I got your point.

[Former Member]

Alan,

Instead of creating alias tables, can you create 3 contexts? Without the separate alias tables, can I then organize my class structure with only 1 Date class shared amongst the Order, Invoice, Transaction metrics as:

Class:Master Date

Object:Year,SQL: Date.Year

Object:Month,SQL: Date.Month

Object:Day,SQL: Date.Day

Class:Order

(List of Order Metrics)

Class:Invoice

(List of Invoice Metrics)

Class:Transaction

(List of Transaction Metrics)

Which method would you say is a better best practice?

Thanks,

Jimmy

[Former Member]

Hi Jimmy,

It really depends on what you want to do. If you want to have a query that uses mulitple dates, say you wanted to limit by order date and invoice date then the 2 classes are better. Otherwise use your approach. As a rule, I think people find it easier to follow the alias approach easier to follow/describe

Regards

Alan