Blockchain 如何从以太坊区块链中的数据块中检索数据?
我做了一个小型活动注册智能合约(使用solidity()),通过提供我的电子邮件id和我想要的门票数量的详细信息,我购买了一张活动门票。最后,我想知道我怎样才能得到我得到的细节。我正在使用testrpc、truffle和privatenet。 在点击购买后,我在tetrpc终端中获得了这些详细信息 交易: 0x35E92857102B0DBAD4324D1EA57790405EB9BEF956B245C6B7737BC23D011BBlockchain 如何从以太坊区块链中的数据块中检索数据?,blockchain,ethereum,Blockchain,Ethereum,我做了一个小型活动注册智能合约(使用solidity()),通过提供我的电子邮件id和我想要的门票数量的详细信息,我购买了一张活动门票。最后,我想知道我怎样才能得到我得到的细节。我正在使用testrpc、truffle和privatenet。 在点击购买后,我在tetrpc终端中获得了这些详细信息 交易: 0x35E92857102B0DBAD4324D1EA57790405EB9BEF956B245C6B7737BC23D011B 天然气使用量:106532区块编号:5区块时间:2018年2月
天然气使用量:106532区块编号:5区块时间:2018年2月3日星期六 12:05:57 GMT+0530(IST) 我对事务id进行如下解码:
gopi145@ubuntu:~/EventRegistration-POC/EventRegistration$ truffle console
truffle(development)> web3.eth.getTransaction('0x35e92857102b0dbacd43234d1ea57790405eb9bef956b245c6b7737bc23d011b')
{ hash: '0x35e92857102b0dbacd43234d1ea57790405eb9bef956b245c6b7737bc23d011b',
nonce: 4,
blockHash: '0x7c790dae57babfe40d68d8aad94913c2b748501c5734aec86cc3fcf0afc4f154',
blockNumber: 5,
transactionIndex: 0,
from: '0x031e060414a0d2573f5b10bc75c0894d72288292',
to: '0xa88a366e888bbccfb78092957ffc7760bc7c6db1',
value: BigNumber { s: 1, e: 18, c: [ 60000 ] },
gas: 200000,
gasPrice: BigNumber { s: 1, e: 0, c: [ 1 ] },
input: '0xa28f161c00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000b6d40676d61696c2e636f6d000000000000000000000000000000000000000000' }
truffle(development)>
但我没有得到购买时得到的详细信息。请告诉我如何执行此操作?
web3.eth.getTransaction(txHash)
将返回区块哈希、transactionIndex、from、to等交易详细信息
挖掘区块并添加到区块链需要一些时间。所以它不是即时的
如果您想知道区块链中向外部世界添加/修改了任何存储价值,那么我们需要在智能合约中提出en事件
使用Web3JS(JSON-RPC/WS-RPC),您需要注册并侦听事件。当您的交易被挖掘时,您将收到一个事件
事件将存储为日志,与存储相比非常便宜。没有人能够修改事件数据
下面是相同的代码
坚固性代码:
pragma solidity ^0.4.17;
//Contract for storing ticket info
contract TicketRes {
event on_success_booking(address userId, string bookingId, string emailId);
//Ticket info having two storage values i.e email and userID
struct BookingInfo{
string emailId;
address userId;
}
//Map for saving all the info, assuming all ticket has unique id as key. Value is ticket info
mapping(bookingId=>BookingInfo) internal info;
function Book() public {
}
//Method will save all basic info, and will raise event.
function onBookingCompleted(address id, string bookingId, string emailId) public {
info[bookingId] = BookingInfo(emailId,userId);
on_success_booking(id, bookingId, emailId);
}
//You can get info by using bookingid at any point of time.
function getBookingInfo(string bookingId) public constant returns(string, address){
return (info[bookingId].emailId, info[bookingId].userId);
}
}
// Contract deployed address.
var contractAddress = "0x06433f4fc50423f71329597f50fb0a42cfecb11f";
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://127.0.0.1:8545"));
}
//Open build folder and you will find contact json file copy the appropriate JSON and paste it there.
var contractABI = web3.eth.contract(/** ABI Here **/);
//Connected contract to your local network
var contract = contractABI.at(contractAddress);
//Loading booking event function.
var booking_event = web3.sha3('on_success_booking(address,string,string)');
//Watching events, when onBookingCompleted() tran's mined then event get triggered. You can get all previous events also. for that need to apply filters.
booking_event.watch((error, result) => {
if(error){
console.log("error",error);
}
console.log("Result", result); //result.args holds values, result.args.id, result.args.bookingId and result.args.emailid
});
现在Javascript代码:
pragma solidity ^0.4.17;
//Contract for storing ticket info
contract TicketRes {
event on_success_booking(address userId, string bookingId, string emailId);
//Ticket info having two storage values i.e email and userID
struct BookingInfo{
string emailId;
address userId;
}
//Map for saving all the info, assuming all ticket has unique id as key. Value is ticket info
mapping(bookingId=>BookingInfo) internal info;
function Book() public {
}
//Method will save all basic info, and will raise event.
function onBookingCompleted(address id, string bookingId, string emailId) public {
info[bookingId] = BookingInfo(emailId,userId);
on_success_booking(id, bookingId, emailId);
}
//You can get info by using bookingid at any point of time.
function getBookingInfo(string bookingId) public constant returns(string, address){
return (info[bookingId].emailId, info[bookingId].userId);
}
}
// Contract deployed address.
var contractAddress = "0x06433f4fc50423f71329597f50fb0a42cfecb11f";
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://127.0.0.1:8545"));
}
//Open build folder and you will find contact json file copy the appropriate JSON and paste it there.
var contractABI = web3.eth.contract(/** ABI Here **/);
//Connected contract to your local network
var contract = contractABI.at(contractAddress);
//Loading booking event function.
var booking_event = web3.sha3('on_success_booking(address,string,string)');
//Watching events, when onBookingCompleted() tran's mined then event get triggered. You can get all previous events also. for that need to apply filters.
booking_event.watch((error, result) => {
if(error){
console.log("error",error);
}
console.log("Result", result); //result.args holds values, result.args.id, result.args.bookingId and result.args.emailid
});
@MGopi能否请您标记为已解决。。。这将有助于社区找到ans。