Member Avatar for bprosic

I can't accomplish async and await in order to populate array and then show the end result.
When I execute the code, firstly there is an empty array. When I go "refresh", then data is populated.
Obviously async. But I don't know how to write the code
The similar problem is described here
https://community.apigee.com/questions/49199/nodejs-cache-retrieve-data-and-push-to-array.html

My code so far

const express = require('express'); const router = express.Router(); const db = require('../../config'); var async = require('async'); function readDb(nameOfTableInDb, someArray) { // reuse a conneciton to db db.getConnection(function (err, conn) { if (err) { res.json({ "code": 100, "status": "Error in connection DB..." }); return; } let qry = ""; switch (nameOfTableInDb) { case "tblcategories": { qry = "SELECT DISTINCT c.catName, (select COUNT(*) from tblPostCatMap as pp where pp.idcat = c.idcategorie) as summeCat from " + nameOfTableInDb + " as c order by c.catName asc"; break; } case "tblsubcat": { qry = "SELECT DISTINCT c.subCatName, (select COUNT(*) from tblPostCatMap as pp where pp.idSubCat = c.idSubCat) as summeSubcat from " + nameOfTableInDb + " as c order by c.subCatName asc"; break; } } conn.query(qry, function (error, rows) { if (error) { throw error; } // add results from DB to someArray array someArray.push(rows); }); conn.release(); }); return someArray; } router.get('/', function (req, res, next) { var someArray = []; var run = async() => { const data = await readDb("tblcategories", someArray); const data = await readDb("tblsubcat", someArray); console.log("async result:\n" + data); } run(); });
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  • Latest Post Latest Post by sagar_14
Member Avatar for bprosic

Solved like this. 

async function showAllFilters(qry, arrayParams) { // params is array[] let result; try { result = await db.query(qry, arrayParams); } catch (error) { console.log("showAllFilters error: "); console.error(error); } return result; } router.get('/', function (req, res) { // localhost:5000/api/filter let qry = "SELECT DISTINCT c.subCatName, (select COUNT(*) from tblPostCatMap as pp where pp.idSubCat = c.idSubCat) as subcatSumme from tblsubcat as c order by c.subCatName asc"; showAllFilters(qry,[]) .then(r => { // first, you get the count of records of all posts and store into count var var rows = []; rows.push(r); // 357 // do the rest of pagination qry = "SELECT DISTINCT c.catName, (select COUNT(*) from tblPostCatMap as pp where pp.idCat = c.idCategorie) as catSumme from tblcategories as c order by c.catName asc"; showAllFilters(qry, []) .then(r2 => { rows.push(r2); res.render('filter', { rows }); }) .catch(err => { console.log("Err in showing all posts with pagination: " + err); }); }) .catch(err => { console.log("Err in getting the count of all posts: " + err); }); }); module.exports = router;
Member Avatar for sagar_14

Your code is running right i did not show any error on this

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