连接数据库时出错

Question

我正在使用硬币系统做一个机器人，当您尝试将其连接到数据库时出现此错误。
代码：

const Discord = require("discord.js");
const bot = new Discord.Client({disableEveryone: true});
const sql = require("sqlite");
const db = sql.open('./coin.sqlite', { Promise });

db.get(`SELECT * FROM coins WHERE userId = [message.author.id]`).then(row => {
  if (!row) { // Can't find the row.
    db.run("INSERT INTO coins (userId, coins) VALUES (?, ?)", [message.author.id, 0]);
  } else {  // Can find the row.
    let curAmt = Math.floor(Math.random() * 5) +0.3 (row.coins + curAmt);
    if (curAmt > row.coins) {
      row.coins = curAmt;
      db.run(`UPDATE coins SET coins = ${row.coins + curAmt}, WHERE userId = [message.author.id]`);
    }
    db.run(`UPDATE coins SET coins = ${row.coins + curAmt} WHERE userId = [message.author.id]`);
  }
}).catch(() => {
  console.error; // Log those errors.
  db.run("CREATE TABLE IF NOT EXISTS coins (userId TEXT, coins INTEGER)").then(() => {
    db.run("INSERT INTO scores (userId, coins) VALUES (?, ?)", [message.author.id, 0]);
  });
});

bot.login(tokenfile.token);

错误：

db.get(`SELECT * FROM coins WHERE userId = [message.author.id]`).then(row => {
   ^

TypeError: db.get is not a function
    at Object.<anonymous> (C:\Users\Илья\Desktop\JyxoBot\Jyxo\index.js:54:4)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Function.Module.runMain (module.js:693:10)
    at startup (bootstrap_node.js:191:16)
    at bootstrap_node.js:612:3
[nodemon] app crashed - waiting for file changes before starting...

机器人没有运行，我不明白问题出在哪里，我觉得一切正常。

Answer 1

sql.open('./coin.sqlite', { Promise });

返回一个promise，因此当您运行db.get() 时，您实际上是在尝试对该未解决的promise 使用该方法。

你需要做的是：

const Discord = require("discord.js");
const bot = new Discord.Client({disableEveryone: true});
const sql = require("sqlite");
const db = sql.open('./coin.sqlite', { Promise });

sql.open('./coin.sqlite', { Promise })
    .then((db) => {
        runApp(db);               
    }).catch((err) => {
        console.log(err);
        process.exit(1);
    });

const runApp = (db) => {
    client.on("message", message => {
        if (message.author.bot) return;
        if (message.channel.type !== "text") return;
        if (message.content.startsWith("ping")) {
            message.channel.send("pong!");
        }
        db.get(`SELECT * FROM coins WHERE userId = ${message.author.id}`).then(row => {
            if (!row) { // Can't find the row.
                db.run("INSERT INTO coins (userId, coins) VALUES (?, ?)", [message.author.id, 0]);
            } else {  // Can find the row.
                let curAmt = Math.floor(Math.random() * 5) +0.3 (row.coins + curAmt);
                if (curAmt > row.coins) {
                    row.coins = curAmt;
                    db.run(`UPDATE coins SET coins = ${row.coins + curAmt}, WHERE userId = ${message.author.id}`);
                }
                db.run(`UPDATE coins SET coins = ${row.coins + curAmt} WHERE userId = ${message.author.id}`);
            }
       }).catch(() => {
           console.error; // Log those errors.
           db.run("CREATE TABLE IF NOT EXISTS coins (userId TEXT, coins INTEGER)").then(() => {
               db.run("INSERT INTO scores (userId, coins) VALUES (?, ?)", [message.author.id, 0]);
           });
       });

       bot.login(tokenfile.token);

    };
};

这将等待 promise 解析并返回 db 对象。有关详细信息，请参阅https://www.npmjs.com/package/sqlite 上的示例。

您还需要将代码放入不和谐客户端的消息处理程序中，如指南所示：https://anidiotsguide_old.gitbooks.io/discord-js-bot-guide/coding-guides/storing-data-in-an-sqlite-file.html

我还将您的大部分应用代码分离为一个函数，以使其更易于阅读。从 promise 返回的 db 对象被传递到这个函数中，所以它可以被使用。

希望这会有所帮助！