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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

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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.
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
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
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
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
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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.
what is the actual application of fullerenes nowadays?
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.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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