广告系统--db层搭建

有关与mysql交互的db层

1.orm框架 sequelize model-first
db层可以提出来一个数据会话层做接口。
eg：

const Sequelize = require('sequelize');
const config = require('./config');


const sequelize = new Sequelize(config.database, config.username, config.password, {
  host: config.host,
  dialect: 'mysql',
  pool: {
    max: 5,
    min: 0,
    idle: 10000,
  },
});
function defineModel(name, attrs, ...cfg) {
  let ocfg = {};
  if (cfg.length > 0) {
    ocfg = cfg[0];
  }
  ocfg.freezeTableName = true;
  return sequelize.define(name, attrs, ocfg);
}

const TYPES = ['STRING', 'INTEGER', 'BIGINT', 'TEXT', 'DOUBLE', 'DATEONLY', 'BOOLEAN', 'DATE', 'FLOAT'];
const exp = {
  define: defineModel,
  sync: () => {
    sequelize.sync({ force: true });
  },
  query: (sql) => {
    return sequelize.query(sql);
  },
};
for (const i in TYPES) {
  exp[TYPES[i]] = Sequelize[TYPES[i]];
}
module.exports = exp;
====================================
model层通过读取models文件夹下的东西读取相关 model进行操作： 自动化脚本
const fs = require('fs');
const db = require('./db');

const files = fs.readdirSync(`${__dirname}/models`);

const js_files = files.filter(f => f.endsWith('.js'), files);

module.exports = {};
for (const f of js_files) {
  console.log(`import model from file ${f}...`);
  const name = f.substring(0, f.length - 3);
  console.log(name);
  module.exports[name] = require(`${__dirname}/models/${f}`);
}


module.exports.sync = () => {
  db.sync();
};

module.exports.query = (sql) => {
  return db.query(sql);
};