Invalid Input syntax for Integer postgresql error - node.js

Question

I am trying to run the delete query from app.js file to postgresql database but every time I am getting error: invalid input syntax for integer: "undefined"
Below is my app.js file code:
var express = require('express'),
path = require('path'),
bodyParser = require('body-parser'),
cons = require('consolidate'),
dust = require('dustjs-helpers'),
pg = require('pg-promise'),
pgdb = require('pg'),
app = express();
//DB Connection
const config = {
user: 'Nasreen',
database: 'Inventory1',
password: 'test',
port: 5432 //Default port, change it if needed
};
const pool = new pgdb.Pool(config);
//assign dust engine
app.engine('dust', cons.dust);
//set default ext
app.set('view engine', 'dust');
app.set('views', __dirname + '/views');
//set public folder
app.use(express.static(path.join(__dirname, 'public')));
//Body parser middleware
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.get('/', function (req, res) {
pool.connect(function (err, client, done) {
if (err) {
return console.error('error', err)
}
client.query('SELECT * FROM "Products"', function (err, result) {
if (err) {
return console.error('error running query', err);
}
res.render('index', { Products: result.rows });
done();
});
});
});
app.post('/add', function (req, res) {
pool.connect(function (err, client, done) {
if (err) {
return console.error('error', err)
}
client.query('INSERT INTO "Products" ("Name", "Purchase_Qty", "Purchase_Rate") VALUES($1, $2, $3)',
[req.body.Name, req.body.Purchase_Qty, req.body.Purchase_Rate]);
done();
res.redirect('/');
});
});
app.delete('/delete/:ID', function (req, res) {
pool.connect(function (err, client, done) {
if (err) {
return console.error('error', err)
}
client.query('DELETE FROM "Products" WHERE "ID" = $1',
[req.params.ID]);
done();
res.sendStatus(200);
});
});
app.post('/edit', function (req, res) {
pool.connect(function (err, client, done) {
if (err) {
return console.error('error', err)
}
client.query('UPDATE "Products" SET "Name"= $1, "Purchase_Qty"= $2, "Purchase_Rate"= $3 WHERE "ID"= $4',
[req.body.Name, req.body.Purchase_Qty, req.body.Purchase_Rate, req.body.ID]);
done();
res.redirect('/');
});
})
INSERT is working fine with double quotes for column names and table name but delete and edit wont't work.
Can someone plz help!!

Answer 1

You don't need to quote the tables' names and the columns' names.
Change the delete statement to:
"DELETE FROM Products WHERE ID = '$1'";
Change the update statement to:
"UPDATE Products SET Name= '$1', Purchase_Qty= '$2', Purchase_Rate= '$3' WHERE ID= '$4'";
EDIT:
Try this:
client.query(`DELETE FROM "Products" WHERE "ID" = ${req.params.ID}`);
It's a function overloading for query. Using template string should solve the issue.
Instead of:
client.query('DELETE FROM "Products" WHERE "ID" = $1',[req.params.ID]);