so did I... if you model CustomerInfo as an EJB and add a field to it...
won't the DB table that holds this entity have to change to?
JP
> -----Original Message-----
> From: Lauren Commons [mailto:[EMAIL PROTECTED]]
> Sent: Jueves, 01 de Febrero de 2001 18:45
> To: [EMAIL PROTECTED]
> Subject: Re: bean design problem for one to many relationship
>
>
> I believe the problem he was refering to was that your
> Java object might change, not the database table. If
> you change the structure of your Java object, say be
> adding a field, or changin a method signature, you
> won't be able to deserialize the blob retrieved from
> the database.
>
>
> --- "Juan Lorandi (Chile)" <[EMAIL PROTECTED]>
> wrote:
> > 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
> > > >> >
> > > >>
> > > >>
> >
> ==============================================================
> >
> === message truncated ===
>
>
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