def _get_sqlite_col_length(layer, fieldname):
"""
Get the length of a sqlite based column using the metadata
NOTE: SQLITE doesn't support this. And this is a bit of a hack.
NOTE NOTE: Looks for VARCHAR(...) as the datatype which isn't really a
sqlite data type.
:returns: True, length if column is found in table metadata
"""
source = layer.source()
if ".sqlite" not in source:
return False, 0
database = Database.fromLayer(layer)
uri = QgsDataSourceUri(layer.dataProvider().dataSourceUri())
layer = uri.quotedTablename()
try:
tabledata = list(database.query("pragma table_info({})".format(layer)))
for row in tabledata:
if not row['name'] == fieldname:
continue
import re
# Look for varchar(...) so we can grab the length.
match = re.search("VARCHAR\((\d.*)\)", row['type'], re.IGNORECASE)
if match:
length = match.group(1)
return True, int(length)
except DatabaseException:
pass
finally:
database.close()
return False, 0
