在SQLAlchemy中动态构造过滤器

如果这对某人有用，这就是我最终要做的事情：

from flask import requestclass Parser(object):  sep = ';'  # ...  def filter_query(self, query):    model_class = self._get_model_class(query) # returns the query's Model    raw_filters = request.args.getlist('filter')    for raw in raw_filters:      try:        key, op, value = raw.split(self.sep, 3)      except ValueError:        raise APIError(400, 'Invalid filter: %s' % raw)      column = getattr(model_class, key, None)      if not column:        raise APIError(400, 'Invalid filter column: %s' % key)      if op == 'in':        filt = column.in_(value.split(','))      else:        try:          attr = filter( lambda e: hasattr(column, e % op), ['%s', '%s_', '__%s__']          )[0] % op        except IndexError:          raise APIError(400, 'Invalid filter operator: %s' % op)        if value == 'null':          value = None        filt = getattr(column, attr)(value)      query = query.filter(filt)    return query

这涵盖了所有SQLAlchemy列比较器：

• eq

  对于

  ==

• lt

  对于

  <

• ge

  对于

  >=

• in

  对于

  in_

• like

  对于

  like

• 等等

详尽列表及其相应名称可在此处找到。