knex 如何在express 中应用？？

var knex = require('knex')({ client: "mysql", connection: { host: "127.0.0.1", user: "", password: "", database: "test" }, pool: { min: 0, max: 7 } });

var express = require('express'); var app = express(); var router = express.Router();

app.get('/xx', function(req, res, next) { var data ; knex.select('name').from('user') .map(function(data) { data = data; }); res.send(data); }); 这样写必定错误