Re: Conversion of Business Objects to Flat Data Table and Viceversa

Shibu,

Writing the logic for creating all of those joins is going to be quite a
task. The problem is that for every child object in your heiarchy, you are
adding overhead at an exponential rate.

For that part, if I had to do it that way (and I most definitely would
not do it that way), I would check the relationships in the tables. For
each child table, I would query the database structure for the relationship
between the parent/child tables, and then construct the join statement based
on that information, while selecting all of the fields from all of the
tables.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- mvp@xxxxxxxxxxxxxxxxxxxxxxxxxxx

"Shibu" <shibusv@xxxxxxxxx> wrote in message
news:Oha39ZTkFHA.1968@xxxxxxxxxxxxxxxxxxxxxxx
> Hi Nicholas ,
>
> Thanks for your reply.. As you were saying, using attribute mapping can
> make
> the whole thing bit easy.
> In addition to using attributes, I guess I am looking for a logic to
> implement it using a single query containing multiple table joins.
> Like looping through each record to fill child class collections (tree).
>
> And while inserting/updating data I have to iterate through each child
> class
> collection and making PL/SQL call using each row data.
> (I am not sure about calling ORACLE PL/SQL with fields as parameters
> instead of a set of records)
>
> Any suggestions...
> Shibu
>
>
> "Nicholas Paldino [.NET/C# MVP]" <mvp@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote
> in
> message news:uGDPOJTkFHA.2156@xxxxxxxxxxxxxxxxxxxxxxx
>> Shibu,
>>
>> You will have to provide the mapping yourself. This is the reason
>> for
>> data layers. Your objects will have to expose a mechanism by which they
> can
>> say "this value should go in column x of table y".
>>
>> You could use reflection, and name the fields internally to match the
>> columns, and the type to match the table, but I think that wouldn't be a
>> good idea.
>>
>> I recommend using an attribute. You can create a TableAttribute,
> which
>> is applied to the class. Then, you can search through your types for the
>> class that has the table attribute with a table name that matches the
> table
>> part of the column. Once you have that, you can have a ColumnAttribute
>> class which will indicate which field in the class should be populated
> with
>> that value from the table.
>>
>> Then, when storing the values back, you can use reflection just the
> same
>> to determine which columns in which tables are to be written to.
>>
>> Hope this helps.
>>
>>
>> --
>> - Nicholas Paldino [.NET/C# MVP]
>> - mvp@xxxxxxxxxxxxxxxxxxxxxxxxxxx
>>
>>
>> "Shibu" <shibusv@xxxxxxxxx> wrote in message
>> news:%23MGNBBTkFHA.2920@xxxxxxxxxxxxxxxxxxxxxxx
>> > Hi,
>> > I have a situation where I need to convert business objects to a flat
>> > table.
>> > The reverse is also required. I am using c# and
>> > Oracle ODP. I am looking for an easier method to do the below steps.
>> >
>> > Steps I follows for populating Business Objects is as follows
>> > (1) Get a list of records containing various tables joined together
>> > from
>> > DB
>> > using a single PL/SQL
>> > (This is a specific requirement, So cannot change the design)
>> >
>> > Data will be redundent as shown below.
>> >
>> > eg:- COLUMNS
>> > ParentTable.Id, ParentTable.Name, ChildTable1.Id,
>> > ChildTable1.Name, ChildTable2.Id, ChildTable2.Name
>> >
>> > Sample data with respect to the above columns
>> >
>> > 1 "A" 1 "a" 1 "aa"
>> > 1 "A" 1 "a" 2 "bb"
>> > 1 "A" 2 "b" 1 "aa"
>> > 1 "A" 2 "b" 2 "bb"
>> > 1 "A" 2 "b" 3 "cc"
>> > 1 "A" 3 "c" 1 "bb"
>> >
>> > (2) Iterate through each row and applying logic to separate data
> required
>> > to
>> > build Buiness object
>> > Eg., of business object :-
>> >
>> > ParentClass
>> > {
>> > //contains collection of child 1
>> >
>> > }
>> >
>> > Child1_Class
>> > {
>> > //contains Collection of child 2
>> > }
>> >
>> >
>> >
>> > The reverse of this process is done to update/insert records from
> Buiness
>> > objects.
>> >
>> > My requirement is, to know whether there's any mechanism by which i can
>> > convert
>> > Business objects to Flat Table (DataTable) and Viceversa.
>> >
>> > Looking for suggestions
>> > Shibu
>> >
>> >
>>
>>
>
>


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