gistfile1.js

app.get('/', function(req, res, next) {
	if (typeof req.body.foo !== 'boolean') {
		return next (new TypeError());
	}
	
	next()
}, function(req, res, next) {
	mysql.query('select 1', function(err, result) {
		if (err) { return next(err); }
		res.send(result);
	})
});

router.get('/')
	.body({ foo: Boolean })
	.use(function() {
		return this.source('mysql').query('select 1');
	})
.end();