Greetings,
As Chip Wilson pointed out I wanted to use the finder method with an extra
attribute in the entitybean of Table 1 (Collection Type) and a similar
approach in Table 2 .
The question is whether I could query the table2, from table1 entitybean
itself; and populate the extra attribute of Table1 as mentioned above i.e
the attribute would contain the bean references of all the records retrieved
from Table2.Then using an iterate I could get the records of Table2 from the
session bean for each record of Table1.
Here I would like to point out that I am NOT using a CMP Bean but bean
Managed Persistance.Additionally the real time data volumes of the tables
mentioned are very high.So performance is an other Problem.
DATABASE:Informix
Richad,Rickard,Ian any Pointers.......of a better solution????
Richard in your book you have shown a example of this type but I needed a
confirmation
Regards,
SANJAY
[Sanjay Nambiar] ***************************************
> Sanjay !!
>
> Consider this approach and lemme know if it would work better !!!
>
>
> why dont u have table1, table 2, table 3 as cmps with just the normalised
> data and then have "table12" and "table23" which hold the relation between
> the two tables (either "1 and 2" in table12 or "2 and 3" in table23)
>
>
> for example (using the standard tables for ease of explanation)
> _______________________________________________________________________
> table1 |table12 |table2 |table23 |table3
> _______________________________________________________________________
> department |emp-dept |employee |emp-favTEAMS
> |favNFLTEAMS
> _______________________________________________________________________
>
> I know the 3rd table (favourite NFL TEAMS) kinda weird but I had nothing
> else in mind which would serve as a good example
> (;-))
>
> So store the PKs of table1 and table2 in table12 which is a two column
> table.
> The same applies to table2 and table3 utilising table23
>
> This way u can have 3 CMP beans mapping to tables 1,2 and 3
> ** U NEED TO CREATE 2 NEW tables *** 12 and 23 though which would be
> utilised by 2 new CMPs. The primary keys of these 2 tables would be the
> combination of the columns.
>
> U can use these CMPs in your session bean which might get a bit more
> complex
> but atleast you wont have problems with portability since every
> persistent
> bean is Container managed and you dont have to hardcode sql anywhere.
>
> I am not sure about the performance though but I would leave that to the
> gurus like Richard/Rickard/Ian..........
>
> Any comments???
> Regards
> Madhu
>
>
>
>
> -----Original Message-----
> From: Sanjay Nambiar [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, November 17, 1999 6:34 AM
> To: [EMAIL PROTECTED]
> Subject: A question about one to many relationships among tables
>
>
> Hi,
> Our application typically has the following scenario:
>
> 1>For Every Record of Table1 we have multiple records in Table2,in turn
> whose every record has multiple records in Table3.
> As the data volumes are very high,I wanted to know if the approach given
> below is right
> In the entity bean of Table 1 we have an extra attribute of say "Vector
> type" which would contain the bean references of all the entitybeans
> corresponding to Table 2.The same is done for the relationship between
> table
> 2 and table 3
> In the entityBean for Table 1 we query the Table 2 and populate the
> entitybean instances of Table 2 from Table 1 entitybean itself and store
> the
> bean references in the Vector and then this Table 1 entitybean is accessed
> from the sessionbean for all the records.
>
> EJBServer supports bean managed persistence and the database is Informix
>
> Any comments ....or an alternative better approach
> SANJAY Nambiar
>
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