code: def convert_type(self, type):
          
  
          # Default dialect
          mapping = {
              'any': sa.Text,
              'array': None,
              'boolean': sa.Boolean,
              'date': sa.Date,
              'datetime': sa.DateTime,
              'duration': None,
              'geojson': None,
              'geopoint': None,
              'integer': sa.Integer,
              'number': sa.Float,
              'object': None,
              'string': sa.Text,
              'time': sa.Time,
              'year': sa.Integer,
              'yearmonth': None,
          }
  
          # Postgresql dialect
          if self.__dialect == 'postgresql':
              mapping.update({
                  'array': JSONB,
                  'geojson': JSONB,
                  'number': sa.Numeric,
                  'object': JSONB,
              })
  
          # Not supported type
          if type not in mapping:
              message = 'Field type "%s" is not supported'
              raise tableschema.exceptions.StorageError(message % type)
  
          return mapping[type]
docs: Convert type to SQL