app.js

var app = require('express').createServer();
cs="postgres://asdf:@localhost/dogs"
var postgres = require('./lib/postgres-js/lib/postgres-pure'); 
var db = new postgres.Connection(cs);

app.get('/dd', function(req, res){

  db.query("SELECT * FROM dogs;", function (data) { 
    res.send(JSON.stringify(data), { 'Content-Type': 'application/json' }, 200);
  });
});

app.listen(3000);