To get the validators&nominators history record of reward, is trouble

[0xthreebody]

Polkawallet project to need query the record of validators&nominators history reward. is very trouble. Requires underlying support. Or there have any easier way to get this information.

[rphmeier]

You should be able to watch for storage updates to the event storage, and look for reward events.
To look into history, the storage-changes-tree should be possible to inspect.

If your use case is to query for all rewards that have ever happened in the history, then this is an antipattern. What if the chain was 10 million blocks? This query would take ages regardless.

[0xthreebody]

Everyone involved in staking different roles wants to see the data of their own rewards. So I want to store all the reward information for the history in the local database and cache. I can calculate the reward balance of the specified account through the reward rule, but the condition of calculating the rule is to calculate the balance at the historical moment of the account and the staking state. There have some unknown info.