在Hyperledger Fabric中读取（查询）事务流

2 回答

• 2

  您可能需要查看https://github.com/hyperledger/fabric-samples/blob/release/fabcar/query.js，它演示了如何使用Node SDK进行查询 . 您会注意到它使用SDK提供的便捷方法https://fabric-sdk-node.github.io/Channel.html#queryByChaincode__anchor来帮助促进查询 .

  就您在帖子中概述的流程而言，步骤1和2是正确的 .
  此外，用于查询事务的链代码函数通常使用https://godoc.org/github.com/hyperledger/fabric/core/chaincode/shim#Success辅助函数来实际返回查询结果 . 在我上面发布的示例中，https://github.com/hyperledger/fabric-samples/blob/release/fabcar/query.js#L51调用https://github.com/hyperledger/fabric-samples/blob/release/chaincode/fabcar/fabcar.go#L135 .

  只要您符合认可政策，就无需将查询交易的响应发送给订货人 . 感谢Dave Enyeart的以下内容：

  A query is a chaincode invocation which reads the ledger current state but does
  not write to the ledger. The chaincode function may query certain keys on the ledger,
  or may query for a set of keys on the ledger. Since queries do not change ledger state,
  the client application will typically not submit these read-only transactions for ordering,
  validation, and committal. Although not typical, the client application can choose to
  submit the read-only transaction for ordering, validation, and commit, for example if the
  client wants auditable proof on the ledger chain that it had knowledge of specific ledger
  state at a certain point in time. Peers will validate and add the read-only transaction
  to the ledger chain, but there will be no updates to ledger current state.
  

  回复于 2024-04-29T02:47:59+08:00
• 0

  这似乎与您在回答此问题时发布的内容相矛盾：Roles (read+write) in hyperledger

  你在这里描述的行为是有道理的，而上述答案中的行为似乎完全被打破了 . 然而，似乎不允许 Channels 上的读者执行调用 .

  回复于 2024-04-29T02:47:59+08:00