I'm currently working on fetching data from a PostgreSQL database using Node.js with the pg package and Angular.
However, I've encountered an issue where making multiple fast calls to the database results in messed up responses. Some of the data appears to be duplicated or even tripled in consecutive responses.
The code used for the call from Angular is quite simple:
$http({
url: "/db?table=appointments&type=perDoctor",
method: "POST"
}).then(...);
On the server-side (using Passport and Express), here's how it's handled:
var pg = require('pg');
var config = {
host: '***',
user: '**',
password: '**',
database: '**',
ssl: true
};
var conString = process.env.DATABASE_URL || config;
var client = new pg.Client(conString);
client.connect();
appointments = [];
var queryString = "SELECT * FROM appointments;"
var query = client.query(queryString);
query.on("row", function(row) {
appointments.push(row);
});
query.on("end", function() {
client.end();
res.send(appointments);
});
As you can see from the image below (although the actual number of records in the database is 502), the results are not as expected: enter image description here