Express js - 无法从 url 获取查询参数（req.query 为空对象）

Question

I know this topic was mentioned here and here but it didn't work for me.

I'm trying to get parameters from URL using req.query . In my server.js file I've got this:

app.get('/reset-pass', function(req,res) {
    console.log(req.url);
    console.log(req.query);
})

When I'm entering URL eg http://localhost:3000/reset-pass?email=anything , server console outputs this:

/reset-pass
[Object: null prototype] {}

and when I fetch from http://localhost:4001/reset-pass , browser console outputs empty object:

data {
    "query": {}
}

As you can see I run my node server on 4001 port and client site on 3000 (because I'm running React on that port) and it's working well doing POST requests or redirects, but in GET case it doesn't return query params. Any weird # do not appear in my path (or I just don't know it).

What's wrong with it?

Answer 1

Try

req.query.email

Hope this solves your issue

Answer 2

There must be another problem in your code. Because i just tested as you did, totally same route.

router.get('/reset-pass', function (req, res) {
    console.log(req.url);
    console.log(req.query);
    res.json({
        url: req.url,
        query: req.query,
    });
});

Returns as:

{
    "url": "/reset-pass?email=anything",
    "query": {
        "email": "anything"
    }
}

And console.log as:

And it's ok. There is no problem with this operation. You should check other parts of your code.

Answer 3

I've figured out what was wrong.

Everything was perfectly fine with server. When I typed query in browser using server port, not client port ( http://localhost:4001/reset-pass?email=anything ), console.log in server terminal outputs everything correctly (as douscriptist said) or on page (eg using res.send() ) it displays expected data.

The problem was with displaying URL parameters in React (in client view).

Trying to fetch data was just unnecessary in this case. I should have used React Router specifying routes like this:

App.js

<Router>
    <Switch>
        <Route exact path="/" component={Main} />
        <Route path="/reset-pass">
            <Route path="/:email" component={ResetPass} />
        </Route>
        <Route component={NoMatch} />
    </Switch>
</Router>

And then in ResetPass.js using match and location I'm able to display query parameters. For quick pars URL string I've added query-string module

ResetPass.js

import React, { Fragment } from "react";
import queryString from "query-string";

const ResetPass = ({ match, location }) => {
    console.log("MATCH", match);
    console.log("LOCATION", location);
    const parsed = queryString.parse(location.search);
    return (
        <Fragment>
            <p>Params: {parsed.email}</p> {/* => Params: anything*/}
        </Fragment>
    );
};

export default ResetPass;

So when I enter URL http://localhost:3000/reset-pass?email=anything , console.log (in browser) returns this:

MATCH {path: "/:email", url: "/reset-pass", isExact: true, params: {email: "reset-pass"}}
LOCATION {pathname: "/reset-pass", search: "?email=anything", hash: "", state: undefined}

I hope that I've explained everything correctly.