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SELECT column_name

FROM all_constraints ac, all_cons_columns acc

WHERE ac.table_name = 'NombreTabla'

AND ac.constraint_type = 'P'

AND ac.constraint_name = acc.constraint_name

ORDER BY acc.position;

El resultado de esta consulta es una fila para cada atributo que forma parte de la clave primaria. Dichos atributos se desplegarán en orden ascendente según su posición, para así poder ingresarlos en el orden por el cual fueron definidos.

A continuación se obtendrán los atributos que forman las claves foráneas de una tabla, y las tablas a las cuales hace referencia dicha clave foránea perteneciente a una determinada tabla, que se llamará nuevamente NombreTabla.

SELECT ac.constraint_name, column_name, r_constraint_name

FROM all_constraints ac, all_cons_columns acc

WHERE ac.table_name = 'NombreTabla'

AND ac.constraint_type = 'R'

AND ac.constraint_name = acc.constraint_name

ORDER BY acc.position;

Como resultado se obtiene una fila por cada atributo que compone a una clave foránea. Cada constraint (clave foránea en este caso) tendrá tantas filas como atributos los compongan. Por cada columna tenemos la siguiente información en el siguiente orden: nombre del constraint, nombre del atributo y nombre del constraint al cual hace referencia.

A partir de los constraints a los cuales se hacen referencia, se puede obtener fácilmente a que tabla pertenecen por medio de la siguiente consulta:

SELECT table_name

FROM all_constraints

WHERE constraint_name = 'NombreConstraint'

Con la consulta anterior obtenemos a que tabla pertenece el constraint NombeConstraint y por lo tanto, si una clave foránea hace referencia al constraint NombreConstraint, entonces ahora sabemos a que tabla hace referencia dicha clave foránea.

Finalmente, para la carga de datos sólo falta averiguar cuales son los atributos que componen a las claves únicas. Para esto se realiza la siguiente consulta:

SELECT ac.constraint_name, column_name

FROM all_constraints ac, all_cons_columns acc

WHERE ac.table_name = 'NombreTabla'

AND ac.constraint_type = 'U'

AND ac.constraint_name = acc.constraint_name

ORDER BY acc.position;

La consulta anterior devuelve todas las claves únicas que existen en una tabla. Cada clave única tendrá tantas filas en el resultado de la consulta como atributos la compongan. El significado de las columnas es el siguiente: nombre del constraint (o sea, de la clave única en este caso) y nombre del atributo.

Análisis de las tablas

A continuación se presenta como determinar que representación conceptual tiene una tabla dada. Es decir, por ejemplo, una tabla puede ser considerada una entidad, una relación binaria, una relación ternaria, una categorización, etc.

En general, el siguiente análisis debe ser realizado por todas las tablas. Como guía, se presenta un diagrama de flujo, que es el que se debe seguir a la hora de analizar una tabla. Es decir, a una tabla dada se le realizarán ciertas pruebas y en función de los resultados de dichas pruebas decidiremos que 'camino' del diagrama de flujo seguir.

A continuación se presenta el diagrama de árbol que sirve de ayuda a la hora de realizar el análisis.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
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Source:  OpenStax, Técnicas de mantenimiento de software. OpenStax CNX. Jan 09, 2009 Download for free at http://cnx.org/content/col10571/1.6
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