Обсуждение: drop table and references
I have a big doubt. If I drop a table with a primary key to which other tables reference to, what happens? And If I create the table again, just as it was, but maybe with another column? Saludos... ;-) -- System Administration: It's a dirty job, but someone told I had to do it. ----------------------------------------------------------------- Martín Marqués email: martin@math.unl.edu.ar Santa Fe - Argentina http://math.unl.edu.ar/~martin/ Administrador de sistemas en math.unl.edu.ar -----------------------------------------------------------------
Nooooooooooooooooooooooooooooooooo! If the primary key of that table is foreign key for other tables they have nothing to refer to. It would be like stripping surnames from people in a large city. Regards - Miles Thompson PS Have you checked the SQL sites which have tutorials on denormalization of data? /mt At 05:28 PM 01/09/2001 -0300, Martin A. Marques wrote: >I have a big doubt. If I drop a table with a primary key to which other >tables reference to, what happens? And If I create the table again, just as >it was, but maybe with another column? > >Saludos... ;-) > >-- >System Administration: It's a dirty job, >but someone told I had to do it. >----------------------------------------------------------------- >Martín Marqués email: martin@math.unl.edu.ar >Santa Fe - Argentina http://math.unl.edu.ar/~martin/ >Administrador de sistemas en math.unl.edu.ar >-----------------------------------------------------------------
My pgAdmin is very slow. Help me please. Regards. Giovanni Serrato
On Tue, 9 Jan 2001, Martin A. Marques wrote: > I have a big doubt. If I drop a table with a primary key to which other > tables reference to, what happens? And If I create the table again, just as > it was, but maybe with another column? Theoretically (ie, assuming no bugs), when you drop the table the foreign key constraints are dropped as well. If you recreate the table the constraints are not recreated, you'd have to use ALTER TABLE ADD CONSTRAINT to make them again.
On Tue, 9 Jan 2001, Stephan Szabo wrote: > > On Tue, 9 Jan 2001, Martin A. Marques wrote: > > > I have a big doubt. If I drop a table with a primary key to which other > > tables reference to, what happens? And If I create the table again, just as > > it was, but maybe with another column? > > Theoretically (ie, assuming no bugs), when you drop the table the foreign > key constraints are dropped as well. If you recreate the table the > constraints are not recreated, you'd have to use ALTER TABLE ADD > CONSTRAINT to make them again. I was talking about tables with primary keys to which foreign keys of other tables are referenced to. Any way the primary key has to be recreated, because the column was of type SERIAL. I'm I right? System Administration: It's a dirty job, but someone told I had to do it. ----------------------------------------------------------------- Martín Marqués email: martin@math.unl.edu.ar Santa Fe - Argentina http://math.unl.edu.ar/~martin/ Administrador de sistemas en math.unl.edu.ar -----------------------------------------------------------------