{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How to query the balance from the historical state in a blockchain?","a":"A4In a  blockchain, the method of querying the balance from the historical state is to obtain it by analyzing the transaction records and account state changes in the blockchain. First, the complete transaction history data of the blockchain needs to be obtained, and then, based on the inputs and outputs of the transactions, the balance changes of the account can be traced. This can be achieved by writing smart contracts or using third-party blockchain query APIs. Meanwhile, to ensure the accuracy of the query, consideration needs to be given to the block height, transaction order, and confirmation status of the transactions. During the query process, the sorting and filtering functions of the blockchain can also be utilized to find relevant transaction records more quickly. In summary, querying the balance from the historical state requires deep mining and analysis on the blockchain to ensure the accuracy of the data."}]}],"pr":"918adb352a740be18b461d27aa16215b37ee95caf1b46d447dc9eece83b1bb0e"}