Foreach loop in nodejs - mysql

Question

My Project uses Node JS + My SQL
I am running a simple query that checks whether entries exist in database for some params.
If they exist, it then updates them, else it inserts them.
The problem is, it is entering the last entry n times instead of each being unique.
When updating also, it is not able to identify the right row.
router.post('/feeRegister', asyncMiddleware( async(req, res) => {
let post= {
...........
}
JSON.parse(req.body.fees).forEach((i,index) => {
let sql = `SELECT id, period, amount FROM feeregister WHERE schoolId = '${req.body.schoolId}' AND studentId = '${req.body.student}' AND classes = '${req.body.classes}' AND year = '${req.body.year}' AND type = '${JSON.parse(req.body.fees)[index][1]}';`
pool.query(sql, async(err, results) => {
try{
if(err){ throw err }
if(results){
if(results.length){
console.log('Entry Exists', index, results[0].id)
let post2= {
...............
}
let sql2 = `UPDATE feeregister SET ? WHERE id = '${results[0].id}'`;
pool.query(sql2, post2, async(err, results) => {
try{
if(err){ throw err }
if(results){}
}catch(e){ func.logError(e); res.status(500); return; }
})
}else{
console.log('Entry does not exist', index)
let sql = `INSERT INTO feeregister SET ?`
pool.query(sql, post, async(err, results) => {
try{
if(err){ throw err }
if(results){}
}catch(e){ func.logError(e); res.status(500); return; }
})
}
}
}catch(e){ func.logError(e); res.status(500); return; }
})
});
}))
Iam connecting to database like :
var mysql = require('mysql')
const pool = mysql.createPool({
host: 'localhost',
user: 'root',
database: 'dBName',
password: '',
multipleStatements: true
});
module.exports = pool;

Answer 1

Perhaps you should call the query function with async-await method.
router.post('/feeRegister', asyncMiddleware( async(req, res) => {
let post= {
//
}
JSON.parse(req.body.fees).forEach(async (i,index) => {
let sql = `SELECT id, period, amount FROM feeregister WHERE schoolId = '${req.body.schoolId}' AND studentId = '${req.body.student}' AND classes = '${req.body.classes}' AND year = '${req.body.year}' AND type = '${JSON.parse(req.body.fees)[index][1]}';`
const promisePool = pool.promise();
let results = await promisePool.query(sql);
if(results){
if(results.length){
console.log('Entry Exists', index, results[0].id)
let post2= {
//
}
let sql2 = `UPDATE feeregister SET ? WHERE id = '${results[0].id}'`;
await promisePool.query(sql2);
}else{
console.log('Entry does not exist', index)
let sql = `INSERT INTO feeregister SET ?`
await promisePool.query(sql);
}
}
});}));