Duda sobre 3 capas en c#+sql server

What exactly do you want me to explain? You say that a 3-tier model
refers to 3 phyiscal tiers and that at the end of the day that's
translated into two logical tiers. That is not the case at all. First
of all, to confuse logical and phyiscal tiers is plain incorrect.
Secondly, to say that in practical terms that is two, then you're
missing entirely the whole point of what a 3 tier system is.

I understand perfectly that you defend to the grave RDMS, good for you,
but that does not imply that a database has to control the business
logic of an application. A 3 tier model is about that, it is about a
middle tier that controls the business logic and leaves the database to
control the INTEGRITY of the DATA. The database doesn't know or doesn't
care whether you are talking about customers or apples.

Data integrity is different to business logic and business logic not
necessarily implies data integrity.

Finally, I have never encountered anyone (apart from my Database
teacher at Univeristy) that in their right mind would go to fifth
normal form in a database. It just become counter-productive.



http://www.hadihariri.com
http://www.malagadnug.org

La cuestión no es si se puede hablar o no de herencia. La autora en
cuestión, quería utilizar el lenjuage orientado a objetos, es decir,
objetos para representar las entitades de su aplicación. >ES una
aproximación no solo válida sino acertada en mi opinion ya que nosotros
pensamos en términos de objetos y no de relacionaes entre tablas. Yo
por lo menos, y lo veo más natural. No creo que sea el único dado la
buena recepción que han tenido los objetos.

"Estructuras" en vez de objetos es quizás el término más apropiado para lo
que dices. Pero eso lo estamos viendo desde Cobol: representar las entidades
(tablas) de la BD en estructuras de la aplicación.
Ahora bien, objeto (o estructura, en este caso) no implica OOP tal como se
la conoce, porque (por lo menos) "donde está la herencia" en eso ?

El libro debe tener 25 años y si bien es cierto de que son conceptos
permanentes en el tiempo siguen siendo 25 años.

Yo no lo he citado, pero continuamente se hace referencia a ella y de
mi ingnorancia sobre SGBD.

No, no es porque lo citaras tu, lo dije porque pienso que no hay que
ubicarse en extremos. Hay otros libros tan valiosos también y más
recientes.

Y no creo que me haya contradicho en ningún mensaje, únicamente en
contestación a otros, he indicado en lo que no estoy en acuerdo con
ellos.

Dije que te contradices en cuanto en vez de seguir sustentando tus
argumentos para evitar que los novatos se confundan (lo que dijiste antes),
decides mejor irte y dejarle el terreno a los que tu consideras equivocados.

Dar nuestro punto de vista es lo que estamos y debemos seguir haciendo todos
aqui. Como dije, es bueno que ustedes los que tienen mayor experiencia que
nosotros los demás, compartan y expresen sus opiniones. Nadie tiene la
verdad absoluta aunque así lo crea. La experiencia particular de cada uno
influye mucho en la perspectiva. Hay que hacer un esfuerzo grande para
romper la barrera de la experiencia particular y conceptualizar otros
escenarios.

"De la discusion nace la luz".

Saludos y exitos.

Hadi Hariri wrote:

What exactly do you want me to explain?

You said :

> This is a classic!
> I rest my case.

What is a classic? What are you referring to? Where is your case?
Having these questions it's very normal to ask for an explanation.
Which by the way you didn't give.

You say that a 3-tier model

refers to 3 phyiscal tiers and that at the end of the day that's
translated into two logical tiers. That is not the case at all.

Yes that is the case at the logical level. (also at the beginning
of the day without any translation)
Business logic, referential integrity, I really don't care how you
call it. *At the end of the day* it all reduces to consistency of the
data. And then you have applications and a database management
system.

First
of all, to confuse logical and phyiscal tiers is plain incorrect.

Indeed.

Secondly, to say that in practical terms that is two, then you're
missing entirely the whole point of what a 3 tier system is.

I did not say anything about 'practical terms'.
You have demonstrated that you are not in a position to tell
anyone with a basic knowledge of information systems and
data management about which points they are missing about
this subject.

I understand perfectly that you defend to the grave RDMS, good for you,

You understand wrong. I would never do such a thing.

but that does not imply that a database has to control the business
logic of an application.

Yeah.. even if I would defend the former, which I don't, that would not
imply the latter. That is true!

1: The database is in control of nothing. The DBMS is.
2: The only 'logic an application' has to care about is the logic
it needs for controlling communications between users and the
rest of the information system, the DBMS.

A 3 tier model is about that, it is about a

middle tier that controls the business logic and leaves the database to
control the INTEGRITY of the DATA.

Nice. But then the business layer and DB storage together ARE the
DBMS. You are splitting a DBMS into a rule system you call middle
tier and a storage device with some integrity control capabilities.
Throwing away many features of the DBMS product in use
by the way.

The database doesn't know or doesn't

care whether you are talking about customers or apples.

You mean "The DBMS doesn't ..."
The application neither, but the users are. So?

Data integrity is different to business logic and business logic not
necessarily implies data integrity.

Data integrity is part of *business logic*, stupid term!;
is part of all the logic needed to enforce the consistency of the
database.

Finally, I have never encountered anyone (apart from my Database
teacher at Univeristy) that in their right mind would go to fifth
normal form in a database. It just become counter-productive.

I didn't say anything about normal forms. You did.

As an aside... did it ever occurred to you that your Databases teacher
is in his right mind and many others are... lets say... searching
for 'cool programming paradigms' that are going so solve their
problems in an 'oh so magical way'... lost... *No silver bullet*

Did you ever consider this as a possibility?

Carlos

"Estructuras" en vez de objetos es quizás el término más apropiado

En que sentido es más apropriado? Es que no veo la complejidad. Deseo
representar unas entidades con objetos.

No, no es porque lo citaras tu, lo dije porque pienso que no hay que
ubicarse en extremos. Hay otros libros tan valiosos también y más
recientes.

Claro que si, y además ese libro en cuestión no es ni muchisimo menos
uno de mis favoritos. Además es demasiado académico.

Dije que te contradices en cuanto en vez de seguir sustentando tus
argumentos para evitar que los novatos se confundan (lo que dijiste
antes), decides mejor irte y dejarle el terreno a los que tu
consideras equivocados.

Porque cuando se empieza con argumentos de ataque personal, y cuando lo
único que se hace es defender una posición sin contemplar que puede
haber otros, es díficil llevar una conversación. Lo que si he hecho es
investigar un poco y he visto que hay numerosas personas que han
entrado (incluso yo mismo en una ocasión pero breve) en una "discusión"
sobre lo mismo con las mismas personas. Viendo que todos han llegado a
la misma conclusión (imposible mantener una discusión en condiciones),
decidí no entrar en el juego. Estoy más que dispuesto a que Carolina o
quien quiera pregunte mi opinión y en privado estaré encantado de
darlo, pero ya no en este grupo de noticia o por lo menos no en esta
hebra ya que lo único que veo son ataques personales.

Dar nuestro punto de vista es lo que estamos y debemos seguir
haciendo todos aqui. Como dije, es bueno que ustedes los que tienen
mayor experiencia que nosotros los demás, compartan y expresen sus
opiniones. Nadie tiene la verdad absoluta aunque así lo crea. La
experiencia particular de cada uno influye mucho en la perspectiva.
Hay que hacer un esfuerzo grande para romper la barrera de la
experiencia particular y conceptualizar otros escenarios.

Plenamente de acuerdo contigo Raul, pero llevo muchisimos anos en lo
que son los foros, intentando ayudar a otras personas, tal como en su
día me ayudaron a mi, y cuando me encuentro con algunas situaciones en
las que es imposible discutir algo, prefiero dejarlo. Pido disculpas si
ha sido malinterpretado como un abandono por falta de argumentos. Y si
tienes cualquier otra pregunta, intentaré responderte en lo que me
permite mis capacidades.

http://www.hadihariri.com
http://www.malagadnug.org

> > This is a classic!
> > I rest my case.

Classic as in this is something that should be kept for historical
reasons, you know "this is a classic" as in ironic. Maybe I should
have put <ironic>This is a classic</ironic>.

"I rest my case" means I will not try and prove your incorrect
assumptions because the declarations you have made are sufficient to
prove they are not correct on their own.

Sorry, I thought you understood these idioms.

call it. *At the end of the day* it all reduces to consistency of the
data. And then you have applications and a database management
system.

No it does not. Data consistency <> Business Logic and it is VERY
important *how you call it*

Indeed.

So then you agree with me your own statement is incorrect?

You have demonstrated that you are not in a position to tell
anyone with a basic knowledge of information systems and
data management about which points they are missing about
this subject.

How so? How have I demonstrated that? Because I don't go around
boasting about my supposed knowledge? Or I don't quote how many authors
I know? Sorry, I don't enter those games.

Yeah.. even if I would defend the former, which I don't, that would
not imply the latter. That is true!

Now I'm lost since it's what you've been defending throughout the
entire thread.

1: The database is in control of nothing. The DBMS is.
2: The only 'logic an application' has to care about is the logic
it needs for controlling communications between users and the
rest of the information system, the DBMS.

You are completely playing with terms here.

The database doesn't know or doesn't
> care whether you are talking about customers or apples.

You mean "The DBMS doesn't ..."
The application neither, but the users are. So?

The business logic should. I don't know what you're trying to get at,
but now trying to pull out of this by twisting what everyone knows and
understands by a DBMS is not working.

As an aside... did it ever occurred to you that your Databases

teacher

is in his right mind and many others are... lets say... searching
for 'cool programming paradigms' that are going so solve their
problems in an 'oh so magical way'... lost... *No silver bullet*

Did you ever consider this as a possibility?

Hardly even understand what you're saying let alone consider it.



http://www.hadihariri.com
http://www.malagadnug.org