How do I send a response from a GET request query from the server-side of an express app?

Question

I am using a query to a postgres db to store the result in a variable in a GET request on the server-side of an Express app.

My query returns the issueID that i am looking for when i run it in psql, but I am having a hard time getting the response to store in a variable so I can send the response to the client side.

My code looks like this:

const pg = require('pg');
const connection = 'postgres://aa2:aa2@localhost:5432/bugtrackingdb';

const client = new pg.Client(connection) ;
client.connect();

    app.get('/tracking', function(req, res) {
    var sql = "SELECT bugtracking.issues.issueID FROM bugtracking.issues WHERE bugtracking.issues.issueID = (SELECT MAX(bugtracking.issues.issueID) FROM bugtracking.issues);"
    var issueID;

    client.query(sql, function(err, result) {
        if (err){
            console.log("error in tracking");
        }

        issueID = JSON.stringify(result.rows[0]);

        console.log("Tracking Result" + issueID);


        //GET results
        res.json(res.statusCode);
        // res.json(issueID);
        console.log("Selected Bug Tracking IssueID. Status Code: " + res.statusCode);
    });
});

How do I get the data from the query to store the data in the issueID variable to send it to the client-side of my app?

I am using body-parser also.

EDIT: It's almost as if the query isn't even executing because I am not able to get my console.log statements to print. This is my front-end code to help understand better:

$(window).load(function() {

    $.ajax({
        type: 'GET',
        url: 'http://139.169.63.170:' + port + '/tracking',
        dataType: 'json',
        cache: true,    

        success: function (data) {

            console.log("DEBUG DONE WITH CAPTURING tacking#: " + data);

            if (data === Number(200)) {
                issueID = issueID + 1;
                $(".trackingID").val(issueID);
            }

        }
    });
    console.log("Window loads & Ajax runs???");
});

2nd EDIT:

Here are the results of running my query in psql. I am trying to get the number '33' to return from my get request:

bugtrackingdb=# SELECT bugtracking.issues.issueID FROM bugtracking.issues WHERE bugtracking.issues.issueID = (SELECT MAX(bugtracking.issues.issueID) FROM bugtracking.issues); 

issueid 
---------
      33
(1 row)

AFter a few changes this is what I am getting to print from the back end console.log statements:

Tracking Result: [object Object]
Selected Bug Tracking IssueID. Status Code: 304

EDIT (Getting closer):

I stringified the result.rows[0] from the object returned from my query. I am now able to get the result to print to the server-side console.log which gives me the following results:

Tracking Result: {"issueid":"37"}
Selected Bug Tracking IssueID. Status Code: 304
status: 200

However, when I uncomment the line res.json(issueID) I get an error.

How do I send my JSON object back to the client side so that I can display it as needed?

Answer 1

app.get('/tracking', function(req, res) {
    var sql = "SELECT bugtracking.issues.issueID FROM bugtracking.issues WHERE bugtracking.issues.issueID = (SELECT MAX(bugtracking.issues.issueID) FROM bugtracking.issues);"
var issueID;

client.query(sql, function(err, result) {
    if (err){
        console.log("error in tracking");
    }

    issueID = JSON.stringify(result.rows[0]);

    console.log("Tracking Result" + issueID);

    // TRY THIS
    res.send(issueID);   
});