flask 的原生语句 筛选条件为None 怎么不作筛选条件

Question

flask 执行原生sql 如果怎么做到如果值为空就不执行这个筛选条件
例如 mysql 的
set @a = ;
if(@a is null , 0=0,find_in_set (a,@a))

flask 的原生语句该怎么写？

Answer 1

class MyBooleanField(wtf.BooleanField):
    def __init__(self, label=None, validators=None, false_values=None, **kwargs):
        # don't accept blank as False, so that default will trigger
        super(MyBooleanField, self).__init__(label, validators, (False, 'false', 0, '0'), **kwargs)

    def process_formdata(self, valuelist):
        if not valuelist or valuelist[0] == '' or valuelist[0] is None:
            self.data = self.default
        elif valuelist[0] in self.false_values:
            self.data = False
        else:
            self.data = True