Ethereum 30303
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
The price of Ethereum has exceeded US $3000. The catalysts behind the rise of Ethereum are as follows:
1 2 3. Virtual currency needs a new leader, and Ethereum is selected by the capital there is an old saying on Wall Street: there is nothing new in the world. What happened in the investment market must have happened before, because the whole financial history has been for hundreds of years. The speculation and investment of virtual currency are similar to stocks, but the risk of virtual currency is greater. The price of Ethereum has exceeded US $3000. The main catalyst behind the rise of Ethereum is the sharp rise of bitcoin and dogcoin. Ethereum, which has always been favored by everyone, has always been in the stage of undervaluation. There is linkage between virtual currencies, and there will be high and low switching. Ethereum has been recognized by market funds as a new virtual currency leader, Funds believe that Ethereum is undervalued and thus driven up by funds, which is the most important catalyst for Ethereum's rise virtual currency is a kind of high-risk and high-yield investment, which is not recommended by general investors. The risk is too big for everyone< br />
When Ethereum broke through the $3000 mark, the bitcoin market caused these impacts:
1. Ethereum broke through and rose $3000, bitcoin and other virtual currencies received more and more attention:
2. Bitcoin and Ethereum are both virtual currencies, and they have linkage effect 3 emerging instries will encounter difficulties in the development process. After these difficulties are solved, new cognition will be formed, which will break everyone's cognition and be accepted by everyone. Bitcoin is like this, from doubt to recognition and then to acceptance. Ethereum broke through the $3000 mark, which had a significant impact on the bitcoin market. The virtual currency has formed a plate effect from bitcoin to dogcoin, and now Ethereum. This shows that the virtual currency is getting more and more attention. There is a strong linkage between virtual currencies. The rise of Ethereum may also stimulate the rise of bitcoin, Finally, the valuation of virtual currency may be greatly improved, which is actually very beneficial to the whole virtual currency there is a lot of controversy about virtual currency now, because no one can control the decentralization, and basically no country recognizes their value, but this has not affected the rise of Ethereum based virtual currency, which is actually the problem of pattern and cognition. For ordinary investors, I do not recommend to participate in virtual currency, which is too risky to grasp< br />