How to query a Postgres DB in node.js (api.ai,node.js)

Question

I have the following function in a node.js app:

if (parameters.hasOwnProperty("brand-param") && parameters["brand-param"] !='') {
    codes.readCodes(function(allCodes) {

the function readCodes is then called and within the function, I query the db:

readCodes: function(callback) {
      var pool = new pg.Pool(config.PG_CONFIG);
      pool.connect(function(err, client, done) {
          if (err) {
              return console.error('Error acquiring client', err.stack);
          }
          client
              .query(
                  `SELECT brand_code FROM public.voucher_codes WHERE brand_name=${parameters.hasOwnProperty("brand-param")} `,
                  function(err, result)

How do I query the db with the content of the “brand-param” for the WHERE part?

Answer 1

1. The variable parameters defined inside apps.js must be passed to readCodes function in order to use it in the query.

2. The check of brand_name is incorrect. It miss the use of single quotes and the parameter value itself is incorrect.

---

if (parameters['brand-param'] && parameters['brand-param'].length) {
    codes.readCodes(parameters, function(allCodes) {

---

readCodes: function(parameters, callback) {
  var pool = new pg.Pool(config.PG_CONFIG);

  pool.connect(function(err, client, done) {
      if (err) {
          return console.error('Error acquiring client', err.stack);
      }

 client.query(
   `SELECT brand_code FROM public.voucher_codes WHERE brand_name='${parameters['brand-param']}' `,
    function(err, result)