[GRASS-user] Re: [GRASSLIST:1140] Re: Qn. on extracting from multiple rasters, data corresponding to vector polygons

Maciej Sieczka tutey at o2.pl
Sun Sep 17 12:16:01 EDT 2006

Hamish wrote:
> Vishal Mehta wrote:

>> echo "DELETE FROM watershed8c COLUMN LIKE 'rain'" | db.execute
>> but they did'nt work.
>> How do i delete say all columns that start with the text 'rain' from a
>> table?

> I'm not sure, but the DBF driver may not support "DELETE" ?

Correct. Neither DROP COLUMN will work. Neither in SQLITE doesn't. A
workaround: http://grass.gdf-hannover.de/wiki/Sqlite_Drop_Column

> Make a new table, copy columns you want to keep, v.db.droptable the old
> table? or use another db?

Postgres and Mysql support DROP COLUMN.


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