Forum Discussion
How to get the data from the blockchain?
Hi. I've successfully set up one application on Azure Blockchain Workbench following the documents.
However, when I edit data in the SQL database, the DLT watcher of the Web app shows the changed records. I suppose that the SQL database is a copy of the Ledger, and the web simply reads from the database.
So how can I get the actual info, which is stored on the Ethereum Ledger, using corresponding BlockHash or TransactionHash? I'm concerned about the safe and unchangeable characteristics of data, which seems not clarified in the public preview documents.
11 Replies
Hi Cheng. The database is meant to be a duplicate of the data stored in the attached blockchain. The database makes it easy to visualize and analyze data on the blockchain. We have a backlog item to add additional information in the database to allow customers to verify whether the data in the database has been modified.
Thanks a lot for your helpful reply. Since neither administrators nor members of the application have access to data stored in the blockchain, does it mean that data are absolutely safe? In other words, how could Azure Blockchain Workbench guarantee that the distributed ledger residing on VMs cannot be changed?
- I guess there is no such guarantee in place, unless access to the replicated storage is strictly write-only and read-only (no updates/deletes) as in the recently announced Azure Storage.
