问题
I'm working on the latest rev of hyperledger-composer (V0.13) and have built a network with multiple roles, each of which can invoke selected transactions within the blockchain. I would now like to query the blockchain (?Historian?) for all transactions which have been executed against a specific Order (defined type of asset).
I've used two different appoaches to pulling Historian data, once through direct API access historian.getall()
and the other through a defined query:
query getHistorianRecords {
description: "get all Historian records"
statement: SELECT org.hyperledger.composer.system.HistorianRecord
}
Both queries succeed in that they return all transactions within the system. per ex:
ValidatedResource {
'$modelManager': ModelManager { modelFiles: [Object] },
'$namespace': 'org.hyperledger.composer.system',
'$type': 'HistorianRecord',
'$identifier': '0c3274475fed3703692bb7344453ab0910686905451b41d5d08ff1b032732aa1',
'$validator': ResourceValidator { options: {} },
transactionId: '0c3274475fed3703692bb7344453ab0910686905451b41d5d08ff1b032732aa1',
transactionType: 'org.acme.Z2BTestNetwork.CreateOrder',
transactionInvoked:
Relationship {
'$modelManager': [Object],
'$namespace': 'org.acme.Z2BTestNetwork',
'$type': 'CreateOrder',
'$identifier': '0c3274475fed3703692bb7344453ab0910686905451b41d5d08ff1b032732aa1',
'$class': 'Relationship' },
eventsEmitted: [],
transactionTimestamp: 2017-09-22T19:32:48.182Z }
What I can't find, and need, is a way to query the history of transactions against a single Order. An Order is defined (partial listing) as follows:
asset Order identified by orderNumber {
o String orderNumber
o String[] items
o String status
...
o String approved
o String paid
--> Provider provider
--> Shipper shipper
--> Buyer buyer
--> Seller seller
--> FinanceCo financeCo
What I'm looking for is a mechanism that will allow me to query the blockchain to get every record pertaining to an Order with orderNumber = '009'
. I can, and have, easily found the current state of Order # 009, but am now looking for the history of transactions against that order. How to I tell Historian, or another service in the hyperledger-composer system, to give me that information?
回答1:
What you are trying to do makes total sense, however the Historian doesn't yet support it. This requirement is being tracked here: https://github.com/hyperledger/composer/issues/991
The plan is to add metadata into the HistorianRecord
to capture the IDs of the assets and participants that where impacted by the transaction along with the operation performed (delete, update, create, read?).
Once that is in place you will be able to query for HistorianRecord
s that reference a given asset/participant id.
回答2:
My work around is to have the transaction emit the results as event and have a query to then fetch the transaction by id from HistorianRecords which will contains the results emitted as event before.
I've posted the detailed answer here: https://github.com/hyperledger/composer/issues/2458#issuecomment-383377837
回答3:
A good workaround would be write a script function to update asset , emit the results as an event . And filter it from the rest endpoint in transactions tab .
回答4:
One workaround solution is to emit an Event for your transaction. Mention ASSET as a field of the event. Please experiment with the following code.
let historian = await businessNetworkConnection.getHistorian();
let historianRecords = await historian.getAll();
for(let i=0; i< historianRecords.length;i++)
{console.log(historianRecords[i].transactionId+ "-----> " + historianRecords[i].eventsEmitted[0].YOUR_ASSET_NAME);}
来源:https://stackoverflow.com/questions/46372302/how-do-i-find-the-history-of-transactions-for-an-asset-in-a-blockchain-implement