节点js和mysql中的多个查询

我正在使用mysql数据库在js节点上工作。 我想在index.j文件中执行查询。 代码工作的两个连接，但是当我添加第三个查询，我不知道在结果[] []内使用什么数字。 你能帮忙吗？ 谢谢。

这里是index.js文件中的代码

router.get('/StudentPage', function (req, res, next) { if (req.session && req.session.user) { pool.getConnection(function (err, connection) { async.parallel([ function (callback) { connection.query('select * from students where Email = ' + connection.escape(req.session.user.Email), callback) }, function (callback) { connection.query('select * from reservations where student_email = ' + connection.escape(req.session.user.Email), callback) }, function (callback) { connection.query('select * from complaint where student_email = ' + connection.escape(req.session.user.Email), callback)} ], function (err, results) { if (!results[0][0]) { req.session.reset(); res.redirect('/'); } else { res.render('student', { title: 'Student Page', userinfo: results[0][0], reservations: results[1][0], complaints: results[2][0]}); } connection.release(); }); }); } else { res.redirect('/'); } }); 

Answer 1

尝试使用键值对象而不是async.parallel的数组

 // an example using an object instead of an array async.parallel({ one: function(callback){ setTimeout(function(){ callback(null, 1); }, 200); }, two: function(callback){ setTimeout(function(){ callback(null, 2); }, 100); } }, function(err, results) { // results is now equals to: {one: 1, two: 2} }); 

例如：

 router.get('/StudentPage', function (req, res, next) { if (req.session && req.session.user) { pool.getConnection(function (err, connection) { async.parallel({ students: function (callback) { connection.query('select * from students where Email = ' + connection.escape(req.session.user.Email), callback) }, reservations: function (callback) { connection.query('select * from reservations where student_email = ' + connection.escape(req.session.user.Email), callback) }, complaints: function (callback) { connection.query('select * from complaint where student_email = ' + connection.escape(req.session.user.Email), callback) } }, function (err, results) { if (!results.students || !results.students[0]) { req.session.reset(); res.redirect('/'); } else { res.render('student', { title: 'Student Page', userinfo: results.students[0], reservations: results.reservations[0], complaints: results.complaints[0] }); } connection.release(); }); }); } else { res.redirect('/'); } });