使用类型修饰符处理与自定义格式之间的转换。而不是
String在定义列时使用此类型。
class MyTime(TypeDecorator): impl = String def __init__(self, length=None, format='%H:%M:%S', **kwargs) super().__init__(length, **kwargs) self.format = format def process_literal_param(self, value, dialect): # allow passing string or time to column if isinstance(value, basestring): # use str instead on py3 value = datetime.strptime(value, self.format).time() # convert python time to sql string return value.strftime(self.format) if value is not None else None process_bind_param = process_literal_param def process_result_value(self, value, dialect): # convert sql string to python time return datetime.strptime(value, self.format).time() if value is not None else None# in your modelclass MyModel(base): time = Column(MyTime(length=7))
