How can I make this work?
I think I should use promises but I don't have much knowledge about them. I've read about them but couldn't create the structure as it's supposed to.
I simply wanna run two different queries on the same table and use the returning values on the same ejs file
app.get('/', (req, res) => {
db.query('SELECT COUNT(*) AS count, FORMAT(SUM(donation_amount),2) AS total FROM donations;', (err, result) => {
if (err) throw err;
let count = result[0].count; //since query column is requested as "count". we can use "count" to get back the raw value
let total = result[0].total;
res.render('home', { count: count, total: total }); // just the file name is enough. ejs engine looks up the file name in the "views" folder
});
db.query('SELECT CONCAT(first_name, ", ", last_name AS latest_donator, donation_amount AS amount FROM donations ORDER BY donation_time LIMIT 1;', (err, result) => {
if (err) throw err;
let donatorName = result[0].latest_donator;
let amount = result[0].amount;
res.render('home', {first_name: donatorName, amount: amount});
});
});
You can only send the response (res.render(...)) once you have the result of both queries. Therefore you may want to do them sequentially like this.
app.get('/', (req, res) => {
db.query('SELECT COUNT(*) AS count, FORMAT(SUM(donation_amount),2) AS total FROM donations;', (err, result) => {
if (err) throw err;
let count = result[0].count; //since query column is requested as "count". we can use "count" to get back the raw value
let total = result[0].total;
db.query('SELECT CONCAT(first_name, ", ", last_name AS latest_donator, donation_amount AS amount FROM donations ORDER BY donation_time LIMIT 1;', (err, result) => {
if (err) throw err;
let donatorName = result[0].latest_donator;
let amount = result[0].amount;
res.render('home', { first_name: donatorName, amount: amount, count: count, total: total });
});
});
});
But the queries are independent from eachother so you could run them in parallel.