SQLAlchemy如何使用标识值智能地减少查询

Question

以下示例中，学校模型具有唯一字段“key” 一旦我打电话给School.get（1）， 当我再次打电话给School.get（1）时。 没有查询，这很好。 但是当打电话时学校.get_by_key（'gxu'） 查询电话。

我想要的是，因为“密钥”是唯一的，所以SQLALchemy可以聪明不再查询吗？

In [3]: school = School.get(1)
INFO-2013-06-14 18:08:17,903:BEGIN (implicit)
INFO-2013-06-14 18:08:17,904:SELECT school_info._id AS school_info__id, school_info."key" AS school_info_key, school_info.name AS school_info_name 
FROM school_info 
WHERE school_info._id = ?
INFO-2013-06-14 18:08:17,905:(1,)
DEBUG-2013-06-14 18:08:17,906:Col ('school_info__id', 'school_info_key', 'school_info_name')
DEBUG-2013-06-14 18:08:17,906:Row (1, u'gxu', u'\u5e7f\u897f\u5927\u5b66')

In [4]: gxu_school = School.get_by_key('gxu')
INFO-2013-06-14 18:08:32,042:SELECT school_info._id AS school_info__id, school_info."key" AS school_info_key, school_info.name AS school_info_name 
FROM school_info 
WHERE school_info."key" = ?
LIMIT ? OFFSET ?
INFO-2013-06-14 18:08:32,045:(u'gxu', 1, 0)
DEBUG-2013-06-14 18:08:32,046:Col ('school_info__id', 'school_info_key', 'school_info_name')
DEBUG-2013-06-14 18:08:32,047:Row (1, u'gxu', u'\u5e7f\u897f\u5927\u5b66')

In [5]: 

Answer 1

首先，我认为get_by_key（）是0.3或者某种古老的方法吗？时间升级。

接下来，对于任意唯一字段的“缓存”，您可以尝试一个配方：UniqueObject。

或者，如果您感觉更有野心，可以使用真实的caching setup。