def gen(geo, geometry_type=None):
features=geofeatures.geo_features(geo)
geo_type_table = {'LineString':'LINESTRING', 'Point':'POINT'}
type_name = { numbers.Integral:'INT', numbers.Real:'FLOAT', basestring:'TEXT'}
type_rank = { numbers.Integral:1, numbers.Real:2, basestring:3 }
def make_bigint_specs(specs, features, geometry_type):
for (prop,type_name) in specs.items():
if type_name != 'INT': continue
for feature in features:
if feature['geometry']['type'] != geometry_type: continue
if abs(feature['properties'].get(prop,0)) > 2**30:
specs[prop] = 'BIGINT'
break
if not geometry_type: geometry_type = features[0]['geometry']['type']
specs = {}
specs_rank = {}
# auto create 'col types' based on python types of values
# if attribute values not of same type, promote based on type_rank
for feature in features:
if feature['geometry']['type'] != geometry_type: continue
for (prop,value) in feature['properties'].items():
if value==None: continue
if isinstance(value,numbers.Integral): # includes int and long
t = numbers.Integral
elif isinstance(value,numbers.Real):
t = numbers.Real
elif isinstance(value,basestring): # includes unicode
t = basestring
else:
t = basestring # anything weird goes to TEXT.
if specs_rank.get(prop,0) >= type_rank[t]: continue
specs[prop] = type_name[t]
specs_rank[prop] = type_rank[t]
# promote 'INT' attributes with large values to 'BIGINT'
make_bigint_specs(specs, features, geometry_type)
col_specs = sorted(specs.items())
# add geometry as last column
col_specs.append(('geometry', geo_type_table[geometry_type]))
return col_specs
def write_geo(self, geo, table_name, srid=None, geometry_type=None, col_specs=None):
features = geofeatures.geo_features(geo)
if len(features)==0 and not col_specs:
log.warning('Could not write db table %s: zero length and no explicit col_specs', table_name)
return
if not geometry_type: geometry_type = features[0]['geometry']['type']
if not col_specs:
col_specs = colspecs.gen(geo, geometry_type)
#filter features for correct geometry_type
rows = []
for feature in features:
if feature['geometry']['type'] != geometry_type: continue
row = {}
row.update(feature['properties'])
row['geometry'] = feature['geometry']['coordinates']
rows.append(row)
#print 'DEBUG rows', rows
# write the table
self.write_table(table_name, col_specs, rows)
self.commit()
