pg-isnull.js

pgclient.connect(function () {
  pgclient.query('select distinct user_id, gender from users where gender == NULL', function (err, resukt) {
    console.log(result.rows); // []
  });
  pgclient.query('select distinct user_id, gender from users where gender is NULL', function (err, result) {
    console.log(result.rows); // [...]
  });
});