text: var mysql = require('mysql');
  const Categories = require('./categories');
  var DATABASE = 'blog';
  var TABLE = 'images_categories';
  
  //创建连接 
  var client = mysql.createConnection({
      user: 'root',
      password: '123456',
      database: DATABASE
  });
  client.connect();
  module.exports = new Categories(DATABASE, TABLE, client);