I am using node and pg-promise to create a basic rest API and am having some issue querying all data for a particular user. Below is what the data returned should look like. Address, Phone Number, and Skills all live in separate tables. I am having no issue retrieving addresses or phone numbers its just skills I can't seem to get. Not quite sure how to have multiple queries after the main query that gets the user to get all these other fields, please see the attached code for reference and I will be happy to answer any questions.
{
"user_id": 1,
"first_name": "Eugene",
"last_name": "Hanson",
"display_name": "Eugene Hanson",
"email": "ehanson0#typepad.com",
"hash": "88a6aa27235d2e39dd9cb854cc246487147050f265578a3e1aee35be5db218ef",
"privilege_id": 14,
"seniority": 1,
"birthday": "19-11-1940 00:00:00.0",
"shift_count_total": 587,
"shift_count_year": 62,
"address_id": 1,
"street": "92 Schmedeman Lane",
"city": "Fort Smith",
"state": "AR",
"zip": 72905,
"phone_numbers": [
{
"phone_number": "62-(705)636-2916",
"name": "PRIMARY"
}
],
"skills": [
"Head Audio",
"Head Video",
"Head Electrician",
"Carpenter",
"rigger"
]
}
function getAllUsers() {
// console.time("answer time")
var deferred = Q.defer();
db.task(t => {
return t.map('SELECT * \
FROM users \
JOIN addresses \
ON users.address_id = addresses.address_id',[], user => {
var user_id = user.user_id;
// console.log(user_id)
console.time("answer time")
return t.manyOrNone('SELECT phone_numbers.phone_number, phone_types.name \
FROM users \
JOIN users_phone_numbers \
ON users.user_id = users_phone_numbers.user_id \
JOIN phone_numbers \
ON users_phone_numbers.phone_id = phone_numbers.phone_id \
JOIN phone_types \
ON phone_numbers.phone_type_id = phone_types.phone_type_id \
WHERE users.user_id = $1', user.user_id)
.then(phone_numbers=> {
// logger.log('info', phone_numbers)
user.phone_numbers = phone_numbers;
return user;
})
}).then(t.batch);
})
.then(data => {
// console.log(data)
console.timeEnd("answer time");
var response = {code: "200",
message: "",
payload: data};
deferred.resolve(response);
})
.catch(error => {
var response = {code: error.code,
message: error.message,
payload: ""};
logger.log('error', error)
deferred.reject(response)
});
I'm the author of pg-promise.
Simplified version of your function would be:
function getAllUsers() {
return db.task(t => {
return t.map('SELECT * FROM users', [], user => {
return t.batch([
t.any('SELECT * FROM phones'), // plus formatting params
t.any('SELECT * FROM skills'), // plus formatting params
])
.then(data => {
user.phones = data[0];
user.skills = data[1];
return user;
});
}).then(t.batch);
});
}
getAllUsers()
.then(data => {
// data tree
})
.catch(error => {
// error
});
And if you are using bluebird as the promise library, then you can replace this code:
.then(data => {
user.phones = data[0];
user.skills = data[1];
return user;
});
with this one:
.spread((phones, skills) => {
user.phones = phones;
user.skills = skills;
return user;
});
And do not use things like var deferred = Q.defer();, it is not needed there. The library is already promise-based.
For a high-performance alternative see: get JOIN table as array of results with PostgreSQL/NodeJS.
Related
How can I covert following code into .then notation. I wanted to strictly use ".then" notation. That is what I observed with my system.
I raised one question with similar kind of request however, I got the code using async/await. Rather than asking the new requirement over the same thread I initiated this new thread.
Apology for inconvenience. I should have posted this it in first thread itself. Kindly help.
var obj = [{"Id":"10101","descr":"server1.com"},{"Id":"10102","descr":"server2.com"},{"Id":"10103","descr":"server3.com"},{"Id":"10104","descr":"server4.com"},{"Id":"10105","descr":"server5.com"},{"Id":"10106","descr":"server6.com"},{"Id":"10107","descr":"server7.com"}];
var temp = [];
for (var i = 0; i < obj.length; i++){
var id = obj[i].Id;
let response = await fetch('https://abced.com/api/'+id+'/value', {method : "GET", headers: {"Authorization": "xyz"}});
var data = await response.json();
var stats = data.status;
if (stat != "OK")
{
temp.push({Id:obj[i].Id, descr:obj[i].descr, value:"ERROR"})
}
}
console.log(temp);
My expected output is, (values of Id and descr will depends on "if statement" in the code)
[{"Id": "10101","descr": "server1.com","status": "ERROR"},
{"Id": "10103","descr": "server3.com","status": "ERROR"},
{"Id": "10104","descr": "server4.com","status": "ERROR"}]
I tried following but in my system compiler says, "Function declared within loops referencing an outer scope variable mat lead to confusing semantics (Id, descr)"
function fetchMock(url) {
let id = url.split('/')[4];
if ([10101, 10103, 10104].includes(+id)) {
return Promise.resolve({
json() {
return Promise.resolve({
status: 'BAD'
});
}
});
} else {
return Promise.resolve({
json() {
return Promise.resolve({
status: 'OK'
});
}
});
}
}
var obj = [{
"Id": "10101",
"descr": "server1.com"
},
{
"Id": "10102",
"descr": "server2.com"
},
{
"Id": "10103",
"descr": "server3.com"
},
{
"Id": "10104",
"descr": "server4.com"
},
{
"Id": "10105",
"descr": "server5.com"
},
{
"Id": "10106",
"descr": "server6.com"
},
{
"Id": "10107",
"descr": "server7.com"
}
];
function getResults() {
const results = [];
for (let {
Id,
descr
} of obj) {
fetchMock('https://abced.com/api/' + Id + '/value', {
method: "GET",
headers: {
"Authorization": "xyz"
}
}).then(res => res.json()).then(function(data) {
if (data.status !== 'OK') {
results.push({
Id,
descr,
value: 'ERROR'
});
}
});
}
return results;
}
function test() {
const results = getResults();
return results;
}
test();
What is the best way to refactoring code and best performance Here Is what I do In getData function I query get Data from databae using async/await then I got some ugly data I try to map and delete element that duplicate data
async getData({req,res}) {
let data = await this.getData()
data = [
{
"id": 3,
"employee_id": 2290,
"getId": {
"id": 9070
},
"getName": {
"name": "test"
},
},
{
"id": 4,
"employee_id": 2291,
"getId": {
"id": 9070
},
"getName": {
"name": "test"
},
}
] //example I await call database get data look like this
//before I remove them I want to keep duplicate data I set new variable for keep them
//which part is the most ugly is their anyway to do something about this ?
const getId = data[0].getId
const getName = data[0].getName
// in this part I map and delete element that duplicate which is data.getName and data.getId
// I create seperate function for code clean
data = await this.removeElement(data)
//after that I return response data
return response.status(200).json({
status: 200,
success: true,
getId: getId,
getName: getName,
data: data
});
}
async removeElement(data) {
// im not sure is their any beeter way to do something like this ?
return Promise.all(
data.map(async item => {
await delete item.getId;
await delete item.getName;
return item;
})
);
}
so my output response will look like this :
getId : {
id : 9070
}
getName : {
name : 'test'
}
data : [
{
"id": 3,
"employee_id": 2290,
},
{
"id": 4,
"employee_id": 2291,
}
]
I really appreciate for your help thanks
Removing properties from an object is not an asynchronous process. There's no need to await it or have a Promise.all around such a loop.
To extract the two common properties from the first item of the array concisely, you can destructure:
const { getId, getName } = data[0];
Shorthand property names will help too. In full:
const data = await this.getData();
const { getId, getName } = data[0];
const trimmedData = data.map(({ id, employee_id }) => ({ id, employee_id }));
return response.status(200).json({
status: 200,
success: true,
getId,
getName,
data: trimmedData
});
The data.map(({ id, employee_id }) => ({ id, employee_id })) takes the array and constructs a new array of objects which contain only the id and employee_id properties in the original objects.
If you need to blacklist properties rather than extract the desired properties, then you can do something similar to the above with rest syntax:
const trimmedData = data.map(({ getId, getName, ...rest }) => rest);
I'm querying from firebase realtime database, storing each result in an array, and returning this array. While the data is correct, I am not returning it in a type I want it to be in.
The code for this function is
exports.getprojects = functions.https.onRequest((req, res) => {
const uid = req.body.uid;
var projectref = fref.child('projects');
var projarr = [];
// Make the promise object for query
const projpromise = projectref.orderByChild('key').equalTo(uid).once('value');
// Another Promise for pushing to array
const pushpromise = projpromise.then(snap => {
var proj_item = snap.val();
// push to array
projarr.push(proj_item);
return proj_item;
}).catch(reason => {
console.log(reason)
return res.json(400);
})
// Respond with array
return pushpromise.then((proj_item) => {
return res.json(200, projarr);
}).catch(reason => {
console.log(reason)
return res.json(400);
})
});
This function queries all the right data, but returns in format like this :
[
{
"project_id": {
"project_title": "Test Project1",
"project_type": "Long Term"
},
...
]
What I need is for this function to return in format like below :
{
{
"project_id": {
"project_title": "Test Project1",
"project_type": "Long Term"
},
...
}
How can I achieve this? Any help is appreciated. Thank you!
To turn your array into a JSON object with just the key-value pairs, do something like this:
var array = [
{"project_id": {
"project_title": "Test Project1",
"project_type": "Long Term"
}},
{"project_id2": {
"project_title": "Test Project2",
"project_type": "Medium Term"
}},
{"project_id3": {
"project_title": "Test Project3",
"project_type": "Short Term"
}}
];
var result = {};
array.forEach(function(object) {
var key = Object.keys(object)[0];
result[key] = object[key];
})
console.log(result);
I'm trying to make a nested queries with mysql on Node.js with Express, the result should be a json with three nested, the problem is that the return doesn't show me the third nested, my code is:
app.get('/devices/:id', ensureToken, function(req, res){
jwt.verify(req.token, jwt_secret, function(err, data) {
if (err) {
res.sendStatus(403);
} else {
var segment_id = req.param('id');
//Select devices for segment
var ls_devices = 'SELECT d.device_id AS id, d.device_name AS name, d.device_serial AS serial, d.device_description AS description, d.device_key AS keyatom, d.device_type AS type_id, dt.device_type_name AS type, d.device_user_id AS user_id, u.user_name AS username, d.device_segment_id AS segment_id, sg.segment_name, d.device_public AS isPublic, d.device_status AS status FROM ((g_devices d LEFT JOIN g_user u ON u.user_id = d.device_user_id) LEFT JOIN g_device_type dt ON dt.device_type_id = d.device_type) LEFT JOIN g_segments sg ON sg.segment_id = d.device_segment_id WHERE d.device_status = 1 AND sg.segment_id = '+segment_id;
connection.query(ls_devices, function (error, results, fields) {
if (error) throw error;
if(results.length != 0) {
var j = JSON.parse(JSON.stringify(results));
var i = 0;
var d = [];
j.forEach(function(r,index_r){
//
var ls_controllers = 'SELECT c.device_controller_id AS id, c.device_controller_name AS name, c.device_controller_description AS description, c.device_controller_devcon_type AS type_id, ct.devcon_name AS type, ct.devcon_description AS description, d.device_name AS device, d.device_id AS device_id, d.device_serial AS serial, c.device_controller_public AS public, c.device_controller_date_register AS registered, c.device_controller_date AS date, c.device_controller_status AS status FROM (g_device_controller c LEFT JOIN g_device_controller_type ct ON ct.devcon_id = c.device_controller_devcon_type) LEFT JOIN g_devices d ON d.device_id = c.device_controller_device_id WHERE c.device_controller_status = 1 AND d.device_id = '+r.id;
connection.query(ls_controllers, function (error_c, results_c, fields_c) {
var k = JSON.parse(JSON.stringify(results_c));
d.push({device:r.name,controller:[]})
k.forEach(function(r2,index_r2){
d[index_r].controller.push({name:r2.name,action:[]})
var ls_actions = 'SELECT a.action_id AS id, a.action_name AS name, a.action_description AS description, a.action_type AS type_id, aty.action_type_name, aty.action_type_description AS type_description, a.action_controller_device_id AS device_id, a.action_control AS control, a.action_value AS value, a.action_time AS time, a.action_times AS times, a.action_date AS date, a.action_status AS status FROM g_actions a LEFT JOIN g_action_type aty ON aty.action_type_id = a.action_type WHERE a.action_controller_id = '+r2.id;
connection.query(ls_actions, function (error_a, results_a, fields_a) {
if(results_a.length > 0) {
var l = JSON.parse(JSON.stringify(results_a));
l.forEach(function(r3, index_r3){
d[index_r].controller[index_r2].action.push({id_a:r3.id,name_a:r3.name});
console.log(JSON.stringify(d))
});
}
});
});
i ++;
if(i == j.length)
{
return res.json(d);
}
});
})
}
else {
return res.json({devices:false});
}
});
}
});
});
My web response is:
[
{
"device": "device one",
"controller": [
{
"name": "device controller One",
"action": []
}
]
},
{
"device": "device two",
"controller": []
}
]
And the print of the last array push is:
[
{
"device": "device one",
"controller": [
{
"name": "device controller One",
"action": [
{
"id_a": 1,
"name_a": "device action One"
}
]
}
]
},
{
"device": "device two",
"controller": [
]
}
]
k.forEach() does not wait for connection.query() to finish, so effectively the queries are skipped. The remedy is to do something similar to what you did with j.forEach(), but i++ should not happen until all of those finish too.
(Other notes: you could use promises, or async/await and make the flow appear much more neatly, or if you want to stick with learning callbacks you could use async library to simplify some of this)
data= {
"id": 1,
"name": "samuel",
"Manager": [
{
"id": "",
"name": "manager1",
"approvers": [325,134],
}
]
}
FOR this data object , we did the add function using a similar given cypher query in Neo4j
query = "CREATE CONSTRAINT ON (users:user) ASSERT users.name IS UNIQUE";
return cypher(
{
"query": query
}
).then(function () {
query = "CREATE (user:user{ name:"samuel "})
"RETURN user";
action = "create";
return cypher(
{
"query": query,
});
}).then(function (data) {
userId = data[0].user._id;
return Promise.each(data.manager, function (entry) {
query = "MATCH (user: user) WHERE id(user) = " + userId + " " +
" OPTIONAL MATCH (managerApprovers:user) WHERE id(managerApprovers) IN [325,134] " +
"CREATE (manager: managernode {name: "manager1"})<-[:HAS_MANAGER]-(user) " +
"FOREACH (a IN CASE WHEN managerApprovers IS NOT NULL THEN [managerApprovers] ELSE [] END | " +
"CREATE (managerApprovers)<-[:HAS_MANAGE_APPROVER]-(managernode)) RETURN user,managernode";
return cypher(
{
"query": query,
}).then(function (data) {
{
res.action = action;
res.result = data;
return res;
});
}
if we want to update the user name along with updating the manager details and the relation HAS_MANAGE_APPROVER,HAS_MANAGER how is it performed in Neo4j
You have to MATCH the relation, store it in a variable and then SET the property you want:
Match (a:firstNode)-[relation:MY_RELATIONSHIP]->(b:secondNode)
SET relation.variable="Foo"
Keep in mind that using neo4j internal ID is not recommended, see Should we use the Neo4J internal id?