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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