I believe that for the problem presented, the serializable solution is the
best balanced;
ALL approachs have pro's and con's; I just felt this is the most
satisfactory one.
If ContactInfo will be accessed only thru Person, then it won't be needed to
be in a SQL compatible way
also, many DB's do not support an alter table command; so usually adding a
field to a bean results in (a priori) total information loss. Of course,
'old' data could be migrated, but so could be serialized data.
I don't believe in Entity for everything; in many cases it's the best way to
go, but I felt that in this one is just like to kill a chicken with an
A-Bomb.
JP
> -----Original Message-----
> From: Thibault Cuvillier [mailto:[EMAIL PROTECTED]]
> Sent: Jueves, 01 de Febrero de 2001 17:44
> To: [EMAIL PROTECTED]
> Subject: Re: bean design problem for one to many relationship
>
>
> Using serialization to store data in an RDBMS is an horrible and
> hugly solution ! ;)o
> If the structure of your serialized object changed, you will
> not be able
> to reload the serialized object from the DB.
>
> Serialization should be never used for long-term storage.
>
> There is some limitation using BLOB on some application
> servers (such as
> with WLS)
>
> Tibo.
> >-----Original Message-----
> >From: Juan Lorandi (Chile) [mailto:[EMAIL PROTECTED]]
> >Sent: Thursday, February 01, 2001 2:00 PM
> >To: [EMAIL PROTECTED]
> >Subject: Re: bean design problem for one to many relationship
> >
> >
> >yes, you can use object's in CMP...
> >I do that all the time with Orion Server
> >just define the field as java.lang.Object, and the container's
> >persistance
> >manager
> >will serialize the object and store it in a BLOB field in the
> >database (for
> >Oracle, for Sybase & SQL Server it will be image or varbinary).
> >
> >HTH
> >
> >JP
> >
> >PS: Of course, if you try to access the DB directly thru SQL,
> >you will have
> >to deserialize
> >the Object manually. This will present additional difficulties
> >if you aren't
> >using Java.
> >
> >> -----Original Message-----
> >> From: Jianguo Wang [mailto:[EMAIL PROTECTED]]
> >> Sent: Jueves, 01 de Febrero de 2001 16:47
> >> To: [EMAIL PROTECTED]
> >> Subject: Re: bean design problem for one to many relationship
> >>
> >>
> >> Hi,
> >>
> >> When you say that I can put ContactInfo in a Person
> member, you mean
> >> to use BMP, don't you? To my understanding, it is impossible
> >> to use object
> >> as a member in CMP because it can not match a object with a
> >> field in the table.
> >>
> >> Please verify it for me.
> >>
> >> -John
> >>
> >> -----Original Message-----
> >> From: Juan Lorandi (Chile) [SMTP:[EMAIL PROTECTED]]
> >> Sent: Thursday, February 01, 2001 12:56 PM
> >> To: [EMAIL PROTECTED]
> >> Subject: Re: bean design problem for one to many
> relationship
> >>
> >> With this design, you could easily have 2 CMP beans that do
> >> just what you
> >> want.
> >> Alternatively, if contact info will only be accesible thru
> >> Person, you could
> >> store all ContactInfo
> >> in a Person member:
> >>
> >> (very PSEUDO pseudo-code)
> >> public class ContactInfo extends Object {
> >> public String UID;
> >> public String Type;
> >> public String Detail;
> >> }
> >>
> >> and in Person:
> >>
> >> ..
> >> public Vector contactInfoCollection;
> >> ..
> >>
> >> public addContact(ContactInfo contact);
> >> {
> >> contactInfoCollection.add(ContactInfo);
> >> }
> >>
> >>
> >> HTH
> >>
> >> JP
> >> > -----Original Message-----
> >> > From: Jianguo Wang [mailto:[EMAIL PROTECTED]]
> >> > Sent: Jueves, 01 de Febrero de 2001 14:42
> >> > To: [EMAIL PROTECTED]
> >> > Subject: bean design problem for one to many relationship
> >> >
> >> >
> >> > Dear friends,
> >> >
> >> > I have a design problem about one to many relationship. Can
> >> > anyone there give me
> >> > some suggestions,
> >> >
> >> > For simplicity's sake, let's say I have two tables
> >> > Person(UID, FirstName, LastName)
> >> > with primary key (UID) and ContactInfo(UID, Type, Detail)
> >> > with primary key (UID, Type).
> >> > A person may have more than one ContactInfo. For example,
> >> >
> >> > A record in the table "Person" is (777, John, Smith)
> >> > Corresponding to this person, there are two records in the
> >> > table "ContacInfo" like
> >> > (777, Email, [EMAIL PROTECTED])
> >> > (777, Phone, (850)123-4567)
> >> >
> >> > These information are provided at a time and can be saved in
> >> > array (mainly ContactInfo).
> >> > When I try to insert them into database, can I implement it
> >> > as CMP? or I have to
> >> > implement it as BMP? If I can do with CMP, does it mean that
> >> > I have to make a loop
> >> > to invoke home.create(UID, Type, Detail)?
> >> >
> >> > Thank you very much.
> >> >
> >> > -John
> >> >
> >>
> >> ==============================================================
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> >> send email to
> >> [EMAIL PROTECTED] and include in the body of the
> message "help".
> >>
> >
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> >
>
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