Ethereum 当配置有2个网络时，truffle默认迁移到哪个网络？

对于下面的truffle-config.js文件，它在module.exports（development和ropsten）中列出了两个网络，如果我在终端中使用命令truffle migrate而没有明确说明--network development或--network ropsten，那么合同将部署到哪个网络？两者都有

require('dotenv').config();
const Web3 = require("web3");
const web3 = new Web3();
const WalletProvider = require("truffle-wallet-provider");
const Wallet = require('ethereumjs-wallet');

const ropstenPrivateKey = new Buffer(process.env.ROPSTEN_PRIVATE_KEY, "hex")
const ropstenWallet = Wallet.fromPrivateKey(ropstenPrivateKey);
const ropstenProvider = new WalletProvider(ropstenWallet, `https://ropsten.infura.io/${process.env.INFURA_ROPSTEN_ID}`);

module.exports = {
  networks: {
    development: {
      host: "127.0.0.1",
      port: 7545,
      network_id: "*" // Match any network id
    },
    ropsten: {
      provider: ropstenProvider,
      gas: 4600000,
      gasPrice: web3.utils.toWei('55', 'gwei'),
      network_id: "3"
    }
  }
};

如果未指定

--network

，则它仅部署到

开发

。您可以通过运行迁移来确认这一点：

$ truffle migrate
Compiling .\contracts\SimpleContract.sol...
Writing artifacts to .\build\contracts

Using network 'development'.

Network up to date.