When calling this function (right now my order table is empty) I exspect the number 1
let id = 0;
id = await orderNumber();
But the id I get in return is "[object Object]1"
//
// Get MAX order number
//
orderNumber = () => {
return new Promise((resolve, reject) => {
return resolve (orderModel.find().count()+1)
})
}
Anyone have an idea how to avoid that?
My purpose here is just to find the MAX number of records in orderModel (order table) and add 1 to that number.
orderModel.find().count() probably returns a Promise, so you need to await for it to get the actual count:
Note: as mentioned by torbenrudgaard, you're better off using .countDocuments()
orderNumber = async () => {
const count = await orderModel.find().count()
return count + 1
}
or:
orderNumber = () => {
return orderModel.find().count().then(count => count + 1)
}
id = await orderNumber();
orderNumber = () => {
return new Promise((resolve, reject) => {
orderModel.count({}, function(err, result) {
if (err) {
console.log(err);
} else {
res.json("Number of documents in the collection: " + result);
return resolve({
count: result
});
}
});
}
Related
I have code written
function getDetails (req, res) {
const dbQuery = `call spGetSLAReportsDetails('${req.body.domainId}', ${req.body.days},'${req.body.type}','${req.body.app}')`
try {
connectDatabase(dbQuery).then((rows) => {
if (!_.isEmpty(rows.dbData) && !_.isEmpty(rows.dbData[0])) {
const resultList = []
rows.dbData.pop()
var bar = new Promise((resolve, reject) => {
rows.dbData[0].forEach((element, index, array) => {
let query = `select * from YCW.YWFWIC ic where ic.witem=${element.witem} and ic.reqno=${element.reqno};`
connectDatabase(query).then((data) =>{
for (var i = 0; i < data.dbData.length; i++) {
element[data.dbData[i]["cfield"]] = data.dbData[i]["cvalue"]
}
resultList.push(element)
// console.log(resultList)
}).catch((err) => {
console.log(err)
})
if (index === array.length -1) resolve();
});
});
bar.then(() => {
console.log(resultList);
});
res.status(msgCodeJson.ERR004.code).send({
result: resultList })
} else {
console.log("empty array")
res.status(msgCodeJson.ERR004.code).send({
message : "No data found"
})
// httpResponseHandlerError(res, msgCodeJson.ERR001.code, msgCodeJson.ERR001.msg)
}
}).catch(() => {
httpResponseHandlerError(res, msgCodeJson.ERR002.code, msgCodeJson.ERR002.msg)
})
} catch (err) {
httpResponseHandlerError(res, msgCodeJson.ERR009.code, msgCodeJson.ERR009.msg)
}
}
module.exports.getDetails = getDetails
i want data to be fit in resultlist but i get empty list after all operation.
while in foreach loop i am getting proper output.
kindly help in issue.
i tried with async foreach loop but some syntax error is coming.
kindly help
as mentioned in the comment of the code you're using
Best way to wait for .forEach() to complete
This is OK if there is no async processing inside the loop.
yet you have an async function inside your forEach callback, namly this:
connectDatabase(query).then((data) => {
for (var i = 0; i < data.dbData.length; i++) {
element[data.dbData[i]["cfield"]] = data.dbData[i]["cvalue"]
}
resultList.push(element)
}).catch((err) => {
console.log(err)
})
you'll need to resolve the "outer/parent" promise from inside the "inner/child" promise
I suggest using a regular good old for loop and/or checking the count of resolved promises against the rows.dbData[0].length and calling a final code/function once they match
I am trying to return the array shiftInfo from the function csData() within a promise.
function crewsense(){
var request = CS.find({});
request
.then(result => {
var created = result[0].created,
currentTime = moment(),
diff = (currentTime - created);
if(diff < 84600000){
console.log("Current Token is Valid");
var access_token = result[0].access_token;
console.log('Obtaining Crewsense Shift Data');
return access_token
}else{
console.log("Current Token is invalid. Updating Token");
csToken();
}
}).then(access_token => {
csData(access_token) //I am trying to get this function to return async data.
}).then(shiftInfo => { //I want to use the data here.
})
Here is the csData function:
function csData(csKey) {
const dayURL = {
method: 'get',
url: 'https://api.crewsense.com/v1/schedule?start='+today+'%2007:30:00&end='+tomorrow+'%2007:30:00',
headers:{
Authorization: csKey,
}
}
const request = axios(dayURL)
request
.then(result => {
var shiftInfo = [];
var thisShift = [];
var onDuty = result.data.days[moment().format("YYYY-MM-DD")].assignments;
thisShift.push(result.data.days[moment().format("YYYY-MM-DD")].day_color);
var persons = [];
var i = 0;
for(var i=0; i<onDuty.length; i++){
let station = onDuty[i].name
for(var x=0; x<onDuty[i].shifts.length; x++){
var person = {
name: onDuty[i].shifts[x].user.name,
position: onDuty[i].shifts[x].qualifiers[0].name,
station: station
}
persons.push(person);
}
}
shiftInfo = [{thisShift}, {persons}];
// console.log(shiftInfo)
return shiftInfo
})
.catch(error => console.error('csData error:', error))
}
I have attempted assigning var shiftInfo = csData(access_token) w/o success and several other ways to call the csData function. I have attempted reading other like problems on here and I have just ended up confused. If someone can point me in the right direction or please point out the fix I might be able to get it to click in my head.
I appreciate everyone's time.
Thanks!
Whatever you return inside a then, will be passed to the next then callback. If you return a Promise, the result of the promise will be sent to the next then callback:
new Promise((resolve) => {
// We resolve to the value we want
resolve("yay");
}).then((value) => {
// In the first then, value will be "yay"
console.log("First then:", value);
// Then we return a new value "yay x2"
return value + " x2";
}).then((value) => {
// In this second then, we received "yay x2"
console.log("Second then:", value);
// Then we return a promise that will resolve to "yay x2 again"
return new Promise((resolve) => {
setTimeout(() => {
resolve(value + " again");
}, 1000);
});
}).then((value) => {
// After a second (when the returned Promise is resolved) we get the new value "yay x2 again"
console.log("Third then:", value);
// And now we return a Promise that will reject
return new Promise((resolve, reject) => {
setTimeout(() => {
reject(new Error("wtf"));
}, 1000);
});
}).catch((error) => {
// This catch on the whole promise chain will catch any promise rejected
console.log(error.toString());
});
So simply csData must return the promise is creating, and you need to return that promise to the then callback you want:
[...]
}).then(access_token => {
return csData(access_token) //I am trying to get this function to return async data.
}).then(shiftInfo => { //I want to use the data here.
console.log(shiftInfo);
}).catch((err) => {
// Whatever...
});
function csData(csKey) {
[...]
return request.then(result => {
[...]
}
Because you are returning a promise, I recommend you to add the catch outside csData and add it to the promise chain you have before.
I don't know about the correct title for my problem. I just need a value going out of a function, just like return but I think it's not same.
i have code snippet from controller in adonisjs framework:
var nmeadata = "";
jsondata.forEach(element => {
var x = element.nmea
var buff = new Buffer(x, 'base64')
zlib.unzip(buff, (err, res) => {
if(err)
{
//
}
else
{
nmeadata += "greed island"
nmeadata += res.toString()
}
})
});
return view.render('admin.index', {
data: datanmea.toJSON(),
nmea: nmeadata
})
I need the result of unzipped string data that inserted to nmeadata from zlib function then send it to view. But, for this time, even I cannot displaying a simple output like greed island to my view.
thank you.
UPDATE
Still not working after using promises:
class NmeaController {
async index({view})
{
const datanmea = await NmeaModel.all()
const jsondata = datanmea.toJSON()
var promises = [];
var nmeadata = "";
jsondata.forEach(element => {
promises.push(
new Promise(resolve => {
let x = element.nmea
let buff = new Buffer(x, 'base64')
zlib.unzip(buff,
(err, res) => {
if (err) {
//
} else {
nmeadata += "test add text"
// nmeadata += res.toString()
}
//im also try using resolve() and resolve("any text")
resolve(nmeadata);
})
}
)
)
});
await Promise.all(promises);
return view.render('admin.index', {
data: datanmea.toJSON(),
nmea: nmeadata
});
}
UPDATE AUGUST 22 2019
i'm already tried solution from maksbd19 but still not working
class NmeaController {
async index({view})
{
const datanmea = await NmeaModel.all()
const jsondata = datanmea.toJSON()
var promises = [];
var nmeadata = "";
jsondata.forEach(element => {
promises.push(
new Promise(resolve => {
let x = element.nmea
let buff = new Buffer(x, 'base64')
zlib.unzip(buff,
(err, res) => {
if (err) {
// since you are interested in the text only, so no need to reject here
return resolve("");
}
return resolve("greed island")
})
}
)
)
});
const result = await Promise.all(promises); // this will be an array of results of each promises respectively.
nmeadata = result.join(""); // process the array of result
return view.render('admin.index', {
data: datanmea.toJSON(),
nmea: nmeadata
});
}
}
I'd suggest two things-
modify zlib.unzip callback function to resolve properly;
(err, res) => {
if (err) {
// since you are interested in the text only, so no need to reject here
return resolve("");
}
return resolve(res.toString())
}
retrieve the final data from the result of Promise.all
const result = await Promise.all(promises); // this will be an array of results of each promises respectively.
nmeadata = result.join(""); // process the array of result
In this approach every promise will resolve and finally you will get the expected result in array.
I’m working through some inherited code using promises and having a major issue. I have two functions, both returning a promise (or a series of promises in the findOne case), where findAll makes calls to findOne to loop through a number of records to query the data from those records in other tables using Sequelize. I've tried to lay out the code so that all promises passed to findOne are resolved or rejected before returning to the parent function, findAll.
Given a number of matching records in findAll, I pass each record to findOne, which by the time findOne resolves it calls another function, constructJson, which returns a value and not a promise. The issue I'm seeing is that once all records pass through findOne and are returned to findAll, the code actually goes back to the resolve(constructJson(_map, scrub)) line the findOne function a number of times. In my test use case where I’m supposed to be returned four distinct record IDs (that are passed into findOne to be queried), findOne is returning duplicated or out-of-order IDs. I very rarely get the same four sequential IDs returned in the same order they were passed in to findOne, though based on the flow of the function it seems like this should be the case. There is a piece to the asynchronicity I am missing in order to ensure the promise returned by findOne is fully completed the the associated IDs (queries object) passed into it are returned in order. What am I not seeing?
const Sequelize = require('sequelize');
function findAll(dbConn, _map, queries, joins, primaryTable, primaryKey, whereClause, limit, offset, scrub) {
return new Promise((resolve, reject) => {
const sequelize = new Sequelize(dbConn.db, dbConn.username, dbConn.password, dbConn.options);
offset = isNaN(offset) ? 0 : offset;
whereClause = !!whereClause ? ` WHERE true${whereClause}` : ' WHERE true';
sequelize.query(`SELECT count(${primaryKey}) FROM ${primaryTable}${whereClause}`, {type: sequelize.QueryTypes.SELECT})
.then(result => {
totalRows = result[0]["count"];
});
whereClause = isNaN(limit) ? whereClause : whereClause + ` LIMIT ${limit} OFFSET ${offset}`;
sequelize.query(`SELECT ${primaryKey} FROM ${primaryTable}${whereClause}`, {type: sequelize.QueryTypes.SELECT})
.then(matchingRecords => {
let promiseStack = [];
matchingRecords.forEach(record => {
const cloneOfMap = JSON.parse(JSON.stringify(_map));
promiseStack.push(
findOne(dbConn, cloneOfMap, queries, joins, primaryTable, primaryKey, record.id, scrub)
.then(result => {
return result;
})
.catch(error => {
return {err: `error collecting data for id = ${record.id}\n${error}`};
})
)
});
Promise.all(promiseStack).then(bundleEntries => {
sequelize.close();
let errors = bundleEntries.filter(r => {return !!r.err}).map(r => r.err);
if (errors.length === 0) {
resolve(bundleEntries);
} else {
reject("The following queries failed:\n" + errors.join('\n'));
}
});
})
.catch(error => {
sequelize.close();
reject(error);
});
});
}
function findOne(dbConn, _map, queries, joins, primaryTable, primaryKey, id, scrub) {
return new Promise((resolve, reject) => {
let promiseStack = [];
let noMatchesReturned = true;
const sequelize = new Sequelize(dbConn.db, dbConn.username, dbConn.password, dbConn.options);
let queryString;
queries.forEach(query => {
if (!!query.sql && query.sql !== '') {
switch (dbConn.options.dialect) {
case "postgres":
queryString = query.sql + ` WHERE ${primaryTable}.${primaryKey}='${id}' LIMIT 1`;
break;
case "mssql":
queryString = query.sql + ` WHERE ${primaryTable}.${primaryKey}='${id}'`;
break;
}
}
else {
let otherTable = '';
let joinString = '';
if (query.table !== primaryTable) {
otherTable = ", " + primaryTable;
joins.filter(j => {return j.fkTable === primaryTable && j.pkTable === query.table}).forEach(j => {
joinString += ` AND ${j.fkTable}.${j.fkColumn} = ${j.pkTable}.${j.pkColumn}`;
});
}
switch (dbConn.options.dialect) {
case "postgres":
queryString = `SELECT ${query.table}.${query.column} FROM ${query.table}${otherTable} WHERE ${primaryTable}.${primaryKey}='${id}'${joinString} LIMIT 1`;
break;
case "mssql":
queryString = `SELECT TOP 1 ${query.table}.${query.column} FROM ${query.table}${otherTable} WHERE ${primaryTable}.${primaryKey}='${id}'${joinString}`;
break;
}
}
// console.log(queryString);
promiseStack.push(
sequelize.query(queryString, {type: sequelize.QueryTypes.SELECT})
.then(row => {
let newData;
if (row.length === 0) {
newData = null;
} else {
noMatchesReturned = false;
const x = row[0];
const y = Object.keys(x)[0];
newData = x[y];
}
return Object.assign(query, {data: newData});
})
.catch(error => {
return {err: `Error executing query ${error.sql}\n\t${error}`};
})
);
});
Promise.all(promiseStack).then(rows => {
// identify queries that returned an error
sequelize.close();
let errors = rows.filter(r => {return !!r.err}).map(r => r.err);
if (errors.length === 0) {
if (noMatchesReturned) {
resolve([]);
}
else {
// all queries completed without error
rows.forEach(result => {
_map.rows[result.id].data = result.data;
});
resolve(constructJson(_map, scrub));
}
}
else {
sequelize.close();
reject("The following queries failed:\n" + errors.join('\n'));
}
}, error => {
sequelize.close();
reject(error);
});
});
}
I want to build an array of ids from a sqlite query using the node-sqlite3 library.
const sqlite3 = require('sqlite3')
const db = new sqlite3.Database('./db/database-name.db')
let ids = () => {
let sql = `select id from users;`
let result = []
db.each(sql, (err, row) => {
// console.log(row.id)
result.push(row.id)
})
return result
}
console.log(ids())
The console.log() statement prints an empty array. What am I doing wrong?
I was able to achieve the desired result by wrapping the call to db.each with a Promise:
const selectIds = () => {
return new Promise((resolve, reject) => {
let result = []
db.each(`select id from users;`, (err, row) => {
if(err) { reject(err) }
result.push(row.id)
}, () => {
resolve(result)
})
})
}
selectIds().then((ids) => console.log(ids)
You are returning the array before the db.each function finishes. That's why it returns an empty array.
To accomplish the desired result you need to pass a function thats called back when all rows have been pulled.
let ids = () => {
let sql = `select id from users;`
let result = []
db.each(sql, (err, row) => {
result.push(row.id)
}, () => {
console.log(result)
})
}
ids()