Cannot enqueue Query after invoking quit error

Question

I am trying to query my AWS RDS database by getting a value I submit in an html form to pass to the backend and use it in a SQL statement. This is my form:

        Show all 
        <form method="GET" action="/all">
          <select name="all">
            <option value="crimes">Crimes</option>
            <option value="schools">Schools</option>
            <option value="walkscore">Walkscore</option>
          </select>
            data
          <input type="submit" value="GO!">
        </form>

This is my JS code:

app.get('/all',function(req,res){
    var table = req.query['all'];
    connection.query('SELECT * from ' + table, function(err, rows, fields) {
        if(err) {
          console.log(err);
          res.send(500);
        }    
        console.log('The solution is: ', rows);
        connection.end();
        res.send(rows);
    }); 
});

When I do this, it prints in my console after a long time with a list of RowDataPackets, but then it errors out with

Cannot enqueue Query after invoking quit

and

Cannot enqueue Quit after invoking quit.

Clearly it is connecting to the db because I am getting rows. However, it hangs in my browser and gives an internal server error.

How do I fix this to send the response data to the same html page I have my form on for front end parsing?

SLaks SLaks · Accepted Answer · 2017-12-04T18:01:32

You're end()ing the connection in your route handler.

That means you can't use the connection anymore.

You should make a new connection every time.

Cannot enqueue Query after invoking quit error

1 Answers