NodeJs Database Lookup - node.js

Question

I'm using a networking website in node using express and postgresql - using the pg npm module - as my database.
I'm now trying to setup user pages like this:
...
app.get('/u/:u/', function (req, res) {
pool.connect(function(err, client, done) {
...
client.query('SELECT * FROM users WHERE id =($1)', [req.params.u], function(err, result) {
... done(); ...
});
});
});
...
req.params.u returns undefined inside the DB query.
I assume it's because the call back function isn't in the same scope as the app route, how do I get about checking the database like this?
I have a feeling there's a much better way of doing this.

Answer 1

So if the problem is that params gets undefined, the solution should come from something similar to:
...
app.get('/u/:u/', function (req, res) {
var tempReq = req
pool.connect(function(err, client, done) {
...
client.query('SELECT * FROM users WHERE id =($1)',[tempReq.params.u], function(err, result) {
... done(); ...
});
});
});
...

Answer 2

Make sure to put your body-parser code above all the routes in your app.js file to get req.body or req.params or req.query value
var app=express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
extended: false
}));
And your req object is available in your whole route's scope then you can use it in any where in this block no need to store in local variable
app.get('/u/:u/', function (req, res) {
pool.connect(function(err, client, done) {
...
client.query('SELECT * FROM users WHERE id =($1)',[req.params.u], function(err, result) {
... done(); ...
});
});
});

Answer 3

You can communicate with more than one database at a time too
You need ssl first..
var fs = require('fs');
var SSLkey = fs.readFileSync('/local/pem/location/key.pem');
var SSLcert = fs.readFileSync('/local/pem/location/cert.pem');
Now the database code
const mysql = require('mysql');
const forumdb_db = mysql.createConnection({
host: 'localhost',
user: 'dbuser',
password: 'dbpassword',
database: 'dbname',
key: SSLkey,
cert: SSLcert,
connectionLimit: 15,
queueLimit: 30,
acquireTimeout: 1000
});
const inventory_db = mysql.createConnection({
host: 'localhost',
user: 'dbuser',
password: 'dbpassword',
database: 'dbname',
key: SSLkey,
cert: SSLcert,
connectionLimit: 15,
queueLimit: 30,
acquireTimeout: 1000
});
Connecting to databases
inventory_db.connect((err0) => {
inventory_db.query("SELECT `bubblebum` FROM `user_inventory` WHERE `index`='1' LIMIT 1;", function(err0, result0, field0) {
console.log(result0[0].bubblebum);
});
});
forum_db.connect((err0) => {
forum_db.query("SELECT `stars` FROM `user_inventory` WHERE `stars`>'100' LIMIT 1;", function(err1, result1, field1) {
console.log(result1[0].stars);
});
});
There is one problem with this, You'll be disconnected after a while of inactivity so you should set up an interval to send a quick request every ten seconds to the sql server.