[GRASSLIST:9805] Solved: way to drop column in sqlite3
wolfgang.qual at gmx.net
Thu Jan 12 08:00:36 EST 2006
I just found out that there is a way to drop columns in sqlite. It is not this
alter table drop column command, but another one 
CREATE TEMPORARY TABLE t1_backup(a,b);
INSERT INTO t1_backup SELECT a,b FROM t1;
DROP TABLE t1;
CREATE TABLE t1(a,b);
INSERT INTO t1 SELECT a,b FROM t1_backup;
DROP TABLE t1_backup;
It's obvious that this is a little bit complex. But if you use sqlitebrowser,
you will find under -->modify table a button "remove field".
Am Dienstag 10 Januar 2006 pH:20:16 nachmittags/abends schrieb Wolfgang Qual:
> Hi everybody,
> I just read that SQLITE also does not support "ALTER TABLE table DROP
> COLUMN". ("SQLite's version of the ALTER TABLE command allows the user to
> rename or add a new column to an existing table. It is not possible to
> remove a column from a table." 
> How to deal with this issue?
> Best regards,
>  http://www.sqlite.org/lang_altertable.html
> > --- Ursprüngliche Nachricht ---
> > Von: M S <mseibel at gmail.com>
> > An: Markus Neteler <neteler at itc.it>
> > Kopie: GRASS Users List <grasslist at baylor.edu>
> > Betreff: [GRASSLIST:9717] Re: drop column?
> > Datum: Wed, 4 Jan 2006 12:06:46 -0500
> > yes sorry, that was for the DBF driver. shoot, thats too bad. i
> > guess i'd have to (from reading the archives) create a temp table and
> > copy over only the colums I want and then re-attach it? that might be
> > a handy function.
> > anyhow, learning postgres is on my TODO list, so hopefully this issue
> > goes away with more knowledge.
> > thanks!
> > On 1/4/06, Markus Neteler <neteler at itc.it> wrote:
> > > M S wrote:
> > > >is there a drop column command? i didnt see one in the man pages, and
> > > >when i tried the "ALTER TABLE table DROP COLUMN column_name" |
> > > >db.execute it didnt like that command but i was able to add
> > > >columns..
> > >
> > > It depends on the DB driver. I assume that you use DBF? Then it doesn't
> > > work since DBF is very limited. For all other drivers it should
> > (untested).
> > > Markus
More information about the grass-user