Обсуждение: Change table structure.

Hi,

is there any way to change table structure without doing DROP and CREATE
again?

Regards,
MAK.
___________________________________________________________________________
--  Michal A. Kowalski  --  http://www.minfo.com.pl -- mak@minfo.com.pl  --

AFAIK, you can add and and rename columns no problem:

functions=> \h alter table
Command: alter table
Description: add/rename attributes, rename tables
Syntax:
        ALTER TABLE class_name [*] ADD COLUMN attr type
        ALTER TABLE class_name [*] RENAME [COLUMN] attr1 TO attr2
        ALTER TABLE class_name1 RENAME TO class_name2

But you can't drop a column without a DROP and CREATE again.



On Thu, 23 Sep 1999, Michal A. Kowalski wrote:

> Hi,
>
> is there any way to change table structure without doing DROP and CREATE
> again?
>
> Regards,
> MAK.
> ___________________________________________________________________________
> --  Michal A. Kowalski  --  http://www.minfo.com.pl -- mak@minfo.com.pl  --
>
> ************
>

Stuart C. G. Rison
Department of Biochemistry and Molecular Biology
6th floor, Darwin Building, University College London (UCL)
Gower Street, London, WC1E 6BT, United Kingdom
Tel. 0207 504 2303, Fax. 0207 380 7033
e-mail: rison@biochem.ucl.ac.uk

"Michal A. Kowalski" wrote:
>
> Hi,
>
> is there any way to change table structure without doing DROP and CREATE
> again?
nope, only if you rename (table|attr) name(s) or add an attribute.


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Just to add to it...

If you want to drop a column and you do not want to lose data from the
table you may follow the following sequence,

select field1,field2... from TableToBeChanged
into TableToBeChanged_OldData;


where field1,field2... will be having all the columns except the one you
want to delete.

Once it is done you can drop the TableToBeChanged,
and rename TableToBeChanged_OldData to TableToBeChanged.

Hope it helps...

-Cheers,
-Shad.

On Thu, 23 Sep 1999, Stuart Rison wrote:

> AFAIK, you can add and and rename columns no problem:
>
> functions=> \h alter table
> Command: alter table
> Description: add/rename attributes, rename tables
> Syntax:
>         ALTER TABLE class_name [*] ADD COLUMN attr type
>         ALTER TABLE class_name [*] RENAME [COLUMN] attr1 TO attr2
>         ALTER TABLE class_name1 RENAME TO class_name2
>
> But you can't drop a column without a DROP and CREATE again.
>
>
>
> On Thu, 23 Sep 1999, Michal A. Kowalski wrote:
>
> > Hi,
> >
> > is there any way to change table structure without doing DROP and CREATE
> > again?
> >
> > Regards,
> > MAK.
> > ___________________________________________________________________________
> > --  Michal A. Kowalski  --  http://www.minfo.com.pl -- mak@minfo.com.pl  --
> >
> > ************
> >
>
> Stuart C. G. Rison
> Department of Biochemistry and Molecular Biology
> 6th floor, Darwin Building, University College London (UCL)
> Gower Street, London, WC1E 6BT, United Kingdom
> Tel. 0207 504 2303, Fax. 0207 380 7033
> e-mail: rison@biochem.ucl.ac.uk
>
>
> ************
>

Hi,

I'd just like to thank everybody for helping me with problem in subject :).

Greets,
MAK.
___________________________________________________________________________
--  Michal A. Kowalski  --  http://www.minfo.com.pl -- mak@minfo.com.pl  --