sqlite3的封装 - 技术栈

bash 复制代码

cnpm i sqlite3

db.js

javascript 复制代码

// const sqlite3 = require('sqlite3').verbose()
import { Database } from 'sqlite3'
function getDB(dbPath, mCreateTableSql) {
  let createTableSql  = mCreateTableSql
  const setCreateTableSql = (sql) => (createTableSql = sql)
  const setDBPath = (path) => (dbPath = path)

  const db = new Database(dbPath)
  const executeSql = (sql, params) => {
    return new Promise((resolve, reject) => {
      db.run(createTableSql, (err) => {
        if (err) {
          reject(err)
        } else {
          db.all(sql, params, (err, rows) => {
            if (err != null) {
              console.log('sqlite error', err)
              reject(err)
            } else {
              console.log('sqlite success')
              resolve(rows)
            }
          })
        }
      })
    })
  }
  const showTables = async () => {
    return await executeSql('SELECT name FROM sqlite_master WHERE type="table";', [])
  }
  return {
    showTables,
    setCreateTableSql,
    setDBPath,
    executeSql
  }
}

export default getDB

使用db

javascript 复制代码

import getDB from './db.js'
const tableSql=
  'CREATE TABLE IF NOT EXISTS tableName(' +
  'id INTEGER PRIMARY KEY AUTOINCREMENT,' +
  '`name` TEXT NOT NULL);'
const { showTables, setCreateTableSql, setDBPath, executeSql } = getDB("D:/database.db", tableSql)

const test = async () => {
  // const data = await executeSql("select * from tableName", []);
  const data = await executeSql("select * from tableName where name = ?", ['name']);// 传递参数
  const tables = await showTables();
  console.log(tables)
}
test();

踩坑记录：

使用异步函数，想要控制并发数量时，不要不要不要使用数组对象的 forEach方法，用for循环就没问题

javascript 复制代码

async function fun() {
  let tasks = [];
  const taskLimit = 10; // 限制并发数量
  for (let k = 0; k < arr.length; k++) {
    tasks.push(asyncFun(arr[k],globalVar));// 把变量传递给函数调用，防止变量被某个异步函数修改
    if (tasks.length >= taskLimit) {
      await Promise.all(tasks);
      tasks = [];
      console.log("已异步执行", taskLimit, "项任务");
    }
  }
}