Ethereum transaction expiration time

1.

If you want to query the transaction records on the main network, you can use Etherscan. However, if you build your own private chain, how should you query the transaction records

the answer is that you need to listen to the logs on the chain, save them in the database, and then query them in the database. For example:

< pre t = "code" L = "Java" > varaddr = & quot& quot;< br />varfilter=web3.eth.filter({fromB lock:0 ,toBlock:' latest', address:addr });< br />filter.get(function(err,transactions){
transactions.forEach(function(tx){
vartxInfo=web3.eth.getTransaction(tx.transactionHash);
/ / at this time, the transaction information txinfo can be stored in the database
})< br />});

Web3. Eth. Filter() is used to monitor the log on the chain, and Web3. Eth. Gettransaction() is used to extract the information of the specified transaction. Once the transaction information is obtained, it can be stored in the database for query

recommend a practical introction, you can see: Ethereum tutorial

2. With bitpie wallet, this is the largest bitcoin wallet in China. It can buy and sell bitcoin with one click, which is much more convenient than the exchange.

3. Note that Ethereum is 2.0 now. As of 13:57 on the 4th, the current deposit contract address of Ethereum 2.0 has received 1000098eth, and 31252 addresses have completed the mortgage of 32eth. With the increasing number of mortgage, the annual yield of mortgage will graally decrease. After the mortgage amount reaches 1 million eth, the current annualized yield is about 15.7%. Zhongyuan, a well-known exchange, has taken the lead in opening the mining channel of eth2.0 verification node, and then launched qeth. Users can invest their own eth in verification node mining and exchange qeth to obtain liquidity, and then participate in mining. Compared with the disadvantages of eth2.0, qeth has too many things: the liquidity is guaranteed, the user does not have to bear the technical cost, the threshold of participation does not need 32 eth as low as 0.1eth, the nodes are maintained by the platform, and the income is distributed according to eth2.0.

4. Due to the instability of bitcoin price, Ethernet coin has also been affected to some extent. But this will not affect the transaction of ether currency,. In the realm of the Kingdom, whether it is up or down market, as long as you buy the right direction of the transaction, you can make money, which is one of the relatively new investment methods.

5. As a bitcoin trading platform, fire coin has won a round of 10 million RMB capital investment from Zhenge fund, Dai Zhikang, Sequoia Capital (shareholders of many global well-known companies such as apple and Alibaba). Fire coin implements strict risk control management and operates stably. As of the end of 2016, the accumulated turnover of fire currency reached 200 billion yuan
on September 15, 2017, huoyuan.com announced that registration and RMB recharge services will be suspended from now on, and all users will be informed before September 30 that they will stop trading. At the same time, all transactions of digital assets against RMB will be graally stopped before October 31. Fire money network said it will stop virtual currency trading on October 31, 2017. You can contact the fire coin net official consultation refund question
response time: March 11, 2021. Please refer to the official website of Ping An Bank for the latest business changes
[Ping An Bank I know] want to know more? Come and see "Ping An Bank I know" ~
https://b.pingan.com.cn/paim/iknow/index.html

6. 1. The first feature of blockchain is decentralization. How to understand it? Taking the trading book of the foreign exchange trading platform as an example, through the comprehensive and in-depth application of blockchain technology, the foreign exchange trading platform can record all relevant information in a distributed account book, making it difficult for traders to tamper with their trading records, and investors can clearly understand their own capital status and each order transaction, It also changes the opaque trading status of the foreign exchange instry in the past, and is concive to strengthening the competitiveness of the formal and high-quality foreign exchange trading platform
2. The second feature of blockchain is security. Because the blockchain is composed of each encrypted data mole, it has a specific defensive. When the blockchain technology is applied to the safe operation of procts and the management and operation of the platform, this natural security defense mechanism will rece the operation cost of the platform, and the risk coefficient of the platform will be greatly reced
3. When the security and trust are highly solved through blockchain technology, the transnational settlement and transaction efficiency of transactions will undoubtedly be greatly improved. At this time, compared with the past, the foreign exchange trading platform with block chain technology has higher technology content, which can provide more professional service requirements for investors. It's a wonderful thing for investors.

7. " Dream Aquarium & quot; There is a problem: it's not a legally authorized
in other words, it's pirated or unregistered...
the owner should type licensed as ltcensed.

8. All purchases are put in the account uniformly
as long as you remember your purchase cost
how much you sell
you can calculate the profit