What Is Hyperledger Fabric Query?

A Hyperledger Fabric Query is a GET operation provided by a chaincode on a channel on a Hyperledger Fabric network to return the current state of a given asset.

In order to perform a query operation, you need to prepare the following:

• Asset ID - Identifies the Asset for which you want to get the current state.
• Chaincode ID - Identifies the chaincode who manages the given asset.
• Channel ID - Identifies the channel on which the given chaincode is running.
• Peer Address - Identifies the peer who is a member node of the given channel.

The process flow a query operation has 3 major steps:

• Sending Query Request - The client needs to send the query request to the peer based on the peer address. The request must contain all required information listed above.
• Querying Data from World State - The peer runs given chaincode and queries the given asset from the world state. for the current state.
• Returning Query Response - The peer receives the current state of the asset and returns it back the client.

As you can see, a query operation only involves one peer. Other peers and the orderer are not involved.

 

⇒ Interfaces to Communicate with Ledger Peer

⇐ Hyperledger Fabric Process Flow

⇑ Hyperledger Fabric Process Flow

⇑⇑ Hyperledger Tutorials