Support observing changes to single properties

Note these related feature requests:

• #126
• #268

Translation:
I hope to support custom models to query. For example, the storage model is A. I want to use B to accept only some fields of the same name of A to ensure memory overhead. For example, when I do tabular data, I want to query some fields of model A (due to model A There are more than 20 fields) I only want to monitor some of the fields in this model. The current monitoring is full, which will result in a complete model of 20,000 data observations and 200,000 data. For example, I only want to monitor changes and get this Twenty thousand ids, then 20,000 complete model objects will not be generated. This function room provides

Original issue:
希望支持自定义模型来查询 比如存储模型是A 我希望用B 来接受 B只有A的一些同名字段 来保证内存开销

希望支持自定义模型来查询 比如存储模型是A 我希望用B 来接受 B只有A的一些同名字段 来保证内存开销
比如我在做表格数据的时候 希望查询出模型A的部分字段(由于模型A的字段已经超过20个) 我只想监听 这个模型中的部分字段
目前的监听 是全量的 会导致有2万条数据 观察返回也返回了20万条数据的完整模型 比如我只想监听改变而得到这两万个id,那么不会产生2万个完整的模型对象 这个功能room有提供

Inizia esaminando le richieste di funzionalità correlate #126 e #268 e la descrizione tradotta, poiché non sono indicati file sorgente o test. Chiarisci come dovrebbe funzionare l’osservazione delle proprietà selezionate e verifica che il completamento significhi ricevere modifiche o ID senza creare oggetti modello completi per ogni record osservato.