After inserting a row into mysql, I am trying to retrieve the row ID.
con.query('INSERT INTO terminals SET ?', {title: 'test'}, function (err, result, fields) {
console.log(result.insertId);
});
Now I am trying to access result.insertId outside of the function. How is this possbile using async/await?
This didn't work for me:
const response = await con.query('INSERT INTO terminals SET ?', {title: 'test'}, async function (err, result, fields) {
return result;
});
console.log(await response.insertId);
you can create a function that will return a promise.
for example:
function asynqQuery(query, params) {
return new Promise((resolve, reject) =>{
con.query(query, params, (err, result) => {
if (err)
return reject(err);
resolve(result);
});
});
}
try {
const response = await asynqQuery('INSERT INTO terminals SET ?', {title: 'test'});
console.log(response.insertId);
} catch (e) {
console.error
}
Or you can try using "promisify" from the "util" library.
Try with this:
response[0].insertId
in:
const response = await con.query('INSERT INTO terminals SET ?', {title: 'test'}, async function (err, result, fields) {
return result;
});
console.log(response[0].insertId);
Result are always an array almost it have only 1 element
Related
can anyone help me.
I need to get result of queryA [which is an update query that returns ROW_COUNT( )], see if the result is equal to 1.
If not, just return it via res.json
If yes, call queryB [which returns a set of rows].
After which, I have to loop and call queryC to update each row. It has to be one at a time because the queryC is also inserting auditTrails within the stored procedure.
This is the source code:
exports.migrateCustomer = asyncHandler(async (req, res) => {
const { oldCustomerID, newCustomerID, userID } = req.body;
const connection = mysql.createConnection(config);
let sql = `CALL usp_UpdateCustomerCallStatusIdAndIsActive(?,?,?)`;
/*UPDATE Customer*/
const updateCus = connection.query(sql, [oldCustomerID, 'Duplicate', userID], (error, results, fields) => {
if (error) {
return console.error(error.message);
}
return results[0];
});
if (updateCus.rowCount == 1) {
let sql = `CALL usp_GetPurchaseOrderByCustomerIDAndNameSearch(?,?)`;
/*GET rows to be updated*/
const GetRows = connection.query(sql, [oldCustomerID, ''], (error, results, fields) => {
if (error) {
return console.error(error.message);
}
results[0].forEach(element => {
let sql = `CALL usp_UpdatePurchaseOrderByCustomerID(?,?)`;
/*UPDATE rows*/
connection.query(sql, [newCustomerID, userID], (error, results, fields) => {
if (error) {
return console.error(error.message);
}
});
});
});
}
res.json(updateCus);
connection.end();
});
Error:
TypeError: Converting circular structure to JSON
--> starting at object with constructor 'Query'
then another one at the bottom:
throw er; //Unhandled 'error' event
You are missing 'await' before the mysql.createConnection(config) and connection.query call, since these are asynchronous functions. Also in your code connection.end() should be inside the callback.
exports.migrateCustomer = asyncHandler(async (req, res) => {
const { oldCustomerID, newCustomerID, userID } = req.body;
const connection = await mysql.createConnection(config);
let sql = `CALL usp_UpdateCustomerCallStatusIdAndIsActive(?,?,?)`;
/*UPDATE Customer*/
const updateCus = await connection.query(sql, [oldCustomerID, 'Duplicate', userID], (error, results, fields) => {
if (error) {
connection.end();
return console.error(error.message);
}
return results[0];
});
if (updateCus.rowCount == 1) {
let sql = `CALL usp_GetPurchaseOrderByCustomerIDAndNameSearch(?,?)`;
/*UPDATE Customer*/
connection.query(sql, [oldCustomerID, ''], (error, results, fields) => {
if (error) {
connection.end();
return console.error(error.message);
}
results[0].forEach(element => {
let sql = `CALL usp_UpdatePurchaseOrderByCustomerID(?,?)`;
/*UPDATE Customer*/
connection.query(sql, [newCustomerID, userID], (error, results, fields) => {
connection.end();
if (error) {
return console.error(error.message);
}
});
});
});
}else{
connection.end();
return res.status(200).json({
customer:updateCus});
}
});
I try to store the result of my mysql request into and async function (to make something after storing my result) but it's returning undefined.. I don't know why
function hh () {
connection.query('SELECT * FROM `rounds` ', function (error, results, fields) {
if (error) throw error;
// console.log(results)
return results
});
}
async function run() {
connection.connect();
let deter = await hh();
console.log(deter)
connection.end();
}
run();
You're not returning a promise... Try with this code, it could help...
function hh () {
return new Promise((resolve, reject) => {
connection.query('SELECT * FROM `rounds` ', function (error, results, fields) {
if (error) return reject(error);
// console.log(results)
resolve(results)
});
});
}
async function run() {
connection.connect();
let deter = await hh();
console.log(deter)
connection.end();
}
run();
Can't I use promise for nodeJS mysql query?
// My DB settings
const db = require('../util/database');
db.query(sqlQuery, [param1, param2])
.then(result => {
console.log(result);
})
.catch(err => {
throw err;
});
It is returning: TypeError: db.query(...).then is not a function
You mentioned in the comments that you want logic after the query block to be awaited, without placing that logic inside of the callback. By wrapping the method with a Promise, you can do that as such:
try {
const result = await new Promise((resolve, reject) => {
db.query(sqlQuery, (error, results, fields) => {
if (error) return reject(error);
return resolve(results);
});
});
//do stuff with result
} catch (err) {
//query threw an error
}
Something like this should work
function runQuery(sqlQuery){
return new Promise(function (resolve, reject) {
db.query(sqlQuery, function(error, results, fields) {
if (error) reject(error);
else resolve(results);
});
});
}
// test
runQuery(sqlQuery)
.then(function(results) {
console.log(results)
})
.catch(function(error) {
throw error;
});
mysql package does not support promise. We can use then only a function call returns a promise.You can use mysql2 which has inbuilt support for Promise. It will also make your code more readable. From mysql2 docs:
async function main() {
// get the client
const mysql = require('mysql2/promise');
// create the connection
const connection = await mysql.createConnection({host:'localhost',
user: 'root', database: 'test'});
// query database
const [rows, fields] = await connection.execute(query);
// rows hold the result
}
I would aslo recommend you to learn about callbacks, promise and async-await
I trying to execute 2 MySQL queries sequentially in Node.JS. MySQL queries work properly by itself.
I would like to do it with async/await function to be sure record is inserted before it's updated.
Here is the code:
router.post('/assign_new_item_id', async (req, res) => {
.....
try {
let qr1= "INSERT INTO foo1 ........;"
await pool.query( qr1, (err) => {
if (err) throw err;
});
let qr2= "UPDATE foo1 .....;"
await pool.query( qr2, (err) => {
if (err) throw err;
});
}catch(err){
console.log(err)
}
It seems that execution "hangs" within first await await block. What is the best way the ensure that both queries are executed consequently.
Thanks in advance for any help.
To await you need a Promise, Not Callback. In your case you are not returning a promise to await.
router.post('/assign_new_item_id', async (req, res) => {
// .....
try {
let qr1 = "INSERT INTO foo1 ........;"
await new Promise((res, rej) => {
pool.query(qr1, (err, row) => {
if (err) return rej(err);
res(row);
});
});
let qr2 = "UPDATE foo1 .....;"
await new Promise((res, rej) => {
pool.query(qr2, (err, row) => {
if (err) return rej(err);
res(row);
});
});
} catch (err) {
console.log(err)
}
});
Here I am promisifing the pool.query method and returning a promise.
I tried to get result using mysql database query from called function but do not wait for result in called function. Following is my code for users.js file. I got result in getBankDetail function but do not get result in users function.
var db = require("../db/mysqlconnection");
function users(app){
app.get("/users",async function(req, res, next){
let bankDetail = await getBankDetail();
console.log("bankDetail",bankDetail); //Here I do not got result
return res.send(bankDetail);
});
}
async function getBankDetail(){
db.getConnection(async function(err, connection) {
if (err) throw err; // not connected!
await connection.query('SELECT * FROM bank', function (error, results, fields) {
connection.release();
if (error) throw error;
console.log("bank result",results); //Here I got result
return results;
});
});
}
module.exports = users;
My Question is why do not wait for result in called function? I also used async/await functionality.
function getBankDetail(){
return new Promise((resolve, reject) => {
db.getConnection(function(err, connection) {
if (err) reject(err); // not connected!
connection.query('SELECT * FROM bank', function (error, results, fields) {
connection.release();
if (error) reject(err);
console.log("bank result",results); //Here I got result
resolve(results);
});
});
});
}
And then you can use let bankDetail = await getBankDetail();
If you want to use await on your db.getConnection and connection.query you will have to use mysql2/promises library or promisify those functions yourself
Here is the implementation when you use the promisified version of your database driver:
async function getBankDetail(){
const connection = await db.getConnection();
const data = await connection.query('SELECT * FROM bank');
connection.release();
console.log("bank result", data[0]); //Here I got result
return data[0];
}