node.js node-mysql查询不起作用

Question

查询数据库时,我收到此错误:

TypeError: Cannot call method 'query' of undefined
    at Object.<anonymous> (/home/nodeuser/myapp_node/index.js:51:17)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:901:3

我的代码看起来像:

var mysql = require('mysql');
var mysqlConnection = mysql.createConnection({
  host     : 'localhost',
  user     : 'root',
  password : '',
  database : 'carousel',
  debug : true,
}).connect(function(err) {
    if ( !err ) {
        console.log("Connected to MySQL");
    } else if ( err ) {
        console.log(err);
    }
});


var userId = 23

mysqlConnection.query('SELECT * FROM tusers WHERE id = ?', [userId], function(err, results) {
    console.log(err);
    console.log(results);
});

我确保"mysql"在node_modules中.另外,我在控制台中看到"连接到MySQL".

你知道我怎么能做到这一点吗？

Answer 1

您链接到的连接方法mysql.createConnection不会返回连接.相反,你可以这样做:

var mysqlConnection = mysql.createConnection({
  host     : 'localhost',
  user     : 'root',
  password : '',
  database : 'carousel',
  debug : true,
});

mysqlConnection.connect(function(err) {
  if ( !err ) {
    console.log("Connected to MySQL");
  } else if ( err ) {
    console.log(err);
  }
});

或者你可以完全忽略连接调用"也可以通过调用查询来隐式建立连接" - https://github.com/felixge/node-mysql#establishing-connections