如何在节点 js mysql 查询函数中找到匿名函数之外的返回变量值

Hello friend i am new in node js, how we can get variable value used in mysql query anonymous function ?

var alldata = function(){

var http = require('http'), mysql = require('mysql');

var client = mysql.createConnection({
       host: '127.0.0.1',
   user: 'root',
   password: ''
});

client.connect();
client.query("use cakephp2");

client.query("SELECT id, title,body,created from posts", 
        function(err, results, fields) {
            if (err) throw err;

            var output = '<h1>Latest Posts</h1><ul><table border=1><tr>';
            for (var index in fields) {
                output += '<td>' + fields[index].name + '</td>';
            }
            output += '</tr>';
            for (var index in results) {
                output += '<tr><td>' + results[index].id + '</td>';
                output += '<td>' + results[index].title + '</td>';
                output += '<td>' + results[index].body + '</td>';
                output += '<td>' + results[index].created + '</td></tr>';
            }
            output += '</ul>';
            // console.log(output);
            // return output;

        }
    ); 
  return  output ;
}
exports.alldatas = alldata();

在上面的代码中，当使用console.log(output)给出正确的结果时，在client.query中我没有发现返回输出结果，但不能访问匿名函数之外的输出值.