Methods and systems for reading data based on plurality of blockchain networks

1. A computer-implemented method for retrieving data, comprising:

receiving, by a node in a second-type blockchain network, a first-type transaction hash sent by a user, wherein the first-type transaction hash is a hash value of a first-type blockchain transaction associated with a first-type blockchain network;

identifying, by the node based on querying a blockchain of the second-type blockchain network, a second-type blockchain transaction that comprises the first-type transaction hash;

identifying, by the node, a first network identifier from the second-type blockchain transaction;

sending the first-type transaction hash to a first-type blockchain network corresponding to the first network identifier to obtain the first-type blockchain transaction;

providing the first-type blockchain transaction to the user;

receiving, by a node in the second-type blockchain network, a third-type transaction hash sent by the user, wherein the third-type transaction hash is a transaction hash of a third-type blockchain transaction to be retrieved;

identifying, based on querying a blockchain of the second-type blockchain network, a third-type blockchain transaction that comprises the third-type transaction hash;

retrieving a second network identifier from the third-type blockchain transaction;

sending the first-type transaction hash to a third-type blockchain network corresponding to the second network identifier, obtaining a third-type blockchain transaction corresponding to the third-type transaction hash; and

providing the third-type blockchain transaction to the user.

2. The computer-implemented method of claim 1 , wherein the first-type blockchain network and the second-type blockchain network are comprised in a data recording system, the node in the second-type blockchain network and at least one node in the first-type blockchain network are managed by a management entity of the data recording system.

3. The computer-implemented method of claim 2 , wherein in response to receiving data to be recorded, the first-type blockchain network records a first-type blockchain transaction comprising the data on the blockchain of the first-type blockchain network.

4. The computer-implemented method of claim 3 , wherein the node in the second-type blockchain network managed by the management entity of the data recording system sends the second-type blockchain transaction comprising the first-type transaction hash and the first network identifier of the first-type blockchain network to the second-type blockchain network, so as to write the second-type blockchain transaction into the blockchain of the second-type blockchain network.

5. The computer-implemented method according to claim 1 , wherein the third-type blockchain network is comprised in a data recording system, wherein a node in the third-type blockchain network is managed by a management entity of the data recording system, wherein in response to receiving data to be recorded, the third-type blockchain network records the third-type blockchain transaction comprising the data on a blockchain of the third-type blockchain network, and the node in the second-type blockchain network sends the second-type blockchain transaction comprising a hash value of the third-type blockchain transaction and the second network identifier of the third-type blockchain network to the second-type blockchain network, so as to record the second-type blockchain transaction into the blockchain of the second-type blockchain network.

6. The computer-implemented method according to claim 1 , wherein the method further comprises:

receiving, by the second-type blockchain network, data to be recorded; and

recording, by the second-type blockchain network, a second-type blockchain transaction comprising the data on the blockchain of the second-type blockchain network.

7. A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform operations comprising:

receiving, by a node in a second-type blockchain network, a first-type transaction hash sent by a user, wherein the first-type transaction hash is a hash value of a first-type blockchain transaction associated with a first-type blockchain network;

identifying, by the node based on querying a blockchain of the second-type blockchain network, a second-type blockchain transaction that comprises the first-type transaction hash;

identifying, by the node, a first network identifier from the second-type blockchain transaction;

sending the first-type transaction hash to a first-type blockchain network corresponding to the first network identifier to obtain the first-type blockchain transaction;

providing the first-type blockchain transaction to the user;

receiving, by a node in the second-type blockchain network, a third-type transaction hash sent by the user, wherein the third-type transaction hash is a transaction hash of a third-type blockchain transaction to be retrieved;

identifying, based on querying a blockchain of the second-type blockchain network, a third-type blockchain transaction that comprises the third-type transaction hash;

retrieving a second network identifier from the third-type blockchain transaction;

sending the first-type transaction hash to a third-type blockchain network corresponding to the second network identifier, obtaining a third-type blockchain transaction corresponding to the third-type transaction hash; and

providing the third-type blockchain transaction to the user.

8. The non-transitory, computer-readable medium of claim 7 , wherein the first-type blockchain network and the second-type blockchain network are comprised in a data recording system, the node in the second-type blockchain network and at least one node in the first-type blockchain network are managed by a management entity of the data recording system.

9. The non-transitory, computer-readable medium of claim 8 , wherein in response to receiving data to be recorded, the first-type blockchain network records a first-type blockchain transaction comprising the data on the blockchain of the first-type blockchain network.

10. The non-transitory, computer-readable medium of claim 9 , wherein the node in the second-type blockchain network managed by the management entity of the data recording system sends the second-type blockchain transaction comprising the first-type transaction hash and the first network identifier of the first-type blockchain network to the second-type blockchain network, so as to write the second-type blockchain transaction into the blockchain of the second-type blockchain network.

11. The non-transitory, computer-readable medium according to claim 7 , wherein the third-type blockchain network is comprised in a data recording system, wherein a node in the third-type blockchain network is managed by a management entity of the data recording system, wherein in response to receiving data to be recorded, the third-type blockchain network records the third-type blockchain transaction comprising the data on a blockchain of the third-type blockchain network, and the node in the second-type blockchain network sends the second-type blockchain transaction comprising a hash value of the third-type blockchain transaction and the second network identifier of the third-type blockchain network to the second-type blockchain network, so as to record the second-type blockchain transaction into the blockchain of the second-type blockchain network.

12. The non-transitory, computer-readable medium according to claim 7 , wherein the operations further comprises:

receiving, by the second-type blockchain network, data to be recorded; and

recording, by the second-type blockchain network, a second-type blockchain transaction comprising the data on the blockchain of the second-type blockchain network.

13. A computer-implemented system, comprising:

one or more computers; and

one or more computer memory devices interoperably coupled with the one or more computers and having tangible, non-transitory, machine-readable media storing one or more instructions that, when executed by the one or more computers, perform one or more operations comprising:

receiving, by a node in a second-type blockchain network, a first-type transaction hash sent by a user, wherein the first-type transaction hash is a hash value of a first-type blockchain transaction associated with a first-type blockchain network;

identifying, by the node based on querying a blockchain of the second-type blockchain network, a second-type blockchain transaction that comprises the first-type transaction hash;

identifying, by the node, a first network identifier from the second-type blockchain transaction;

sending the first-type transaction hash to a first-type blockchain network corresponding to the first network identifier to obtain the first-type blockchain transaction;

providing the first-type blockchain transaction to the user;

receiving, by a node in the second-type blockchain network, a third-type transaction hash sent by the user, wherein the third-type transaction hash is a transaction hash of a third-type blockchain transaction to be retrieved;

identifying, based on querying a blockchain of the second-type blockchain network, a third-type blockchain transaction that comprises the third-type transaction hash;

retrieving a second network identifier from the third-type blockchain transaction;

sending the first-type transaction hash to a third-type blockchain network corresponding to the second network identifier, obtaining a third-type blockchain transaction corresponding to the third-type transaction hash; and

providing the third-type blockchain transaction to the user.

14. The computer-implemented system of claim 13 , wherein the first-type blockchain network and the second-type blockchain network are comprised in a data recording system, the node in the second-type blockchain network and at least one node in the first-type blockchain network are managed by a management entity of the data recording system.

15. The computer-implemented system of claim 14 , wherein in response to receiving data to be recorded, the first-type blockchain network records a first-type blockchain transaction comprising the data on the blockchain of the first-type blockchain network.

16. The computer-implemented system of claim 15 , wherein the node in the second-type blockchain network managed by the management entity of the data recording system sends the second-type blockchain transaction comprising the first-type transaction hash and the first network identifier of the first-type blockchain network to the second-type blockchain network, so as to write the second-type blockchain transaction into the blockchain of the second-type blockchain network.

17. The computer-implemented system according to claim 13 , wherein the third-type blockchain network is comprised in a data recording system, wherein a node in the third-type blockchain network is managed by a management entity of the data recording system, wherein in response to receiving data to be recorded, the third-type blockchain network records the third-type blockchain transaction comprising the data on a blockchain of the third-type blockchain network, and the node in the second-type blockchain network sends the second-type blockchain transaction comprising a hash value of the third-type blockchain transaction and the second network identifier of the third-type blockchain network to the second-type blockchain network, so as to record the second-type blockchain transaction into the blockchain of the second-type blockchain network.