db.dropcolumn drops a column from an attribute table.
If the -f force flag is not given then nothing is removed, instead
a preview of the action to be taken is printed.
NOTES
db.dropcolumn is a front-end to db.execute to allow easier
usage with a special workaround for the SQLite driver to support column
drop also for SQLite tables.
EXAMPLE
Dropping a column (North Carolina sample dataset):
# work on own copy
g.copy vect=roadsmajor,myroads
db.describe -c myroads
# only shows what would happen:
db.dropcolumn myroads column=SHAPE_LEN
# actually drops the column
db.dropcolumn -f myroads column=SHAPE_LEN
db.describe -c myroads