name mineral opened closed years connected notes
name
mineral
opened
closed
years connected
notes
number parsed year
number parsed year
minimum_number minimum_parsed minimum_year maximum_number maximum_parsed maximum_year
text text date date timespan text
blaen y cwm slate 1820 1911 1876-1911 connected to the ffr via the rhiwbach tramway
how many quarries was slate mined at ?
WRB JJ NNS VBD-AUX NN VBN IN .
20
Keyword Keyword Keyword Keyword Keyword Keyword Keyword Keyword Column Keyword Literal.String
select count ( * ) from w where c2 = 'slate'
Keyword Keyword None None Literal Column None None
['agg', 'agg_count'] ['agg', 'agg_count'] c2