how to fill an array outside the function clause in nodejs - mysql

Question

I want to fill an array outside the function block
app.get('/getpackages/:dateStart/:dateEnd/:limit', function (req, res) {
var xlsSourceFilesRetrievedTsdz = []
var xlsSourceFilesRetrievedSvn = []
var dateStart = req.params.dateStart;
var dateEnd = req.params.dateStart;
var limit = Number(req.params.limit);
let sql = 'SELECT * FROM summary_dz WHERE Start != "" AND Start BETWEEN ? AND ? LIMIT ?'
db.query(sql, [dateStart,dateEnd,limit], function (err, results) {
if (err) throw err;
for (const counter in results) {
xlsSourceFilesRetrievedTsdz.push(results[counter].XlsSourceFile);
}
// console.log(xlsSourceFilesRetrievedTsdz)
});
console.log(xlsSourceFilesRetrievedTsdz)
I want to fill xlsSourceFilesRetrievedTsdz. Whats wrong with what i wrote? I get an emty array. The console.log inside the block in comment gives the wanted result How can the from outside the block?

Answer 1

Doing this should works:
app.get('/getpackages/:dateStart/:dateEnd/:limit', async (req, res) => {
var xlsSourceFilesRetrievedTsdz = []
var xlsSourceFilesRetrievedSvn = []
const promiseQuery = (sql, dateStart, dateEnd, limit) => {
return new Promise((res, rej)=> {
db.query(sql, [dateStart,dateEnd,limit], function (err, results) {
if (err) rej(err);
res(results)
});
})
}
const sql = 'SELECT * FROM summary_dz WHERE Start != "" AND Start BETWEEN ? AND ? LIMIT ?'
const dateStart = req.params.dateStart;
const dateEnd = req.params.dateStart;
const limit = Number(req.params.limit);
const results = await promiseQuery(sql, dateStart, dateEnd, limit)
for (const counter in results) {
xlsSourceFilesRetrievedTsdz.push(results[counter].XlsSourceFile);
}
console.log(xlsSourceFilesRetrievedTsdz)
}
What I do here was wrap the whole thing in a Promise and return it to wait te results.