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Update a record in database after delete with Sequelize Model and NodeJS

i created a controller that can delete but it is difference because it is not only delete records according ID, it also update the record after the API of delete is call.
Let me demonstrate my code below:
// delete user
exports.delete = (req, res) => {
const user_id = req.params.user_id;
// Find record by it is id to DELETE
User.findByPk(user_id).then((num) => {
if (num == 1) {
res.status(200).send({
message: "User was deleted successfully!",
data: null,
});
} else {
res.status(500).send({
message: `Cannot delete User with id=${user_id}. Maybe User was not found!`,
data: null,
});
}
});
//After delete must update the is_active field
User.update(
{
is_active: 0,
},
{
where: { is_active: null },
}
);
};
Now i have problem that i do not know how to make my API to work. So, i hope someone can help me to deal with this problem that how to update is_active MUST BE 0 after DELETE. I am appreciate it.

You just need to use async/await instead of then to wait for then result of findByPk before calling update:
exports.delete = async (req, res) => {
const user_id = req.params.user_id;
// Find record by it is id to DELETE
const user = await User.findByPk(user_id)
if (user) {
//After delete must update the is_active field
await User.update(
{
is_active: 0,
},
{
where: { is_active: null },
}
);
res.status(200).send({
message: "User was deleted successfully!",
data: null,
});
} else {
res.status(500).send({
message: `Cannot delete User with id=${user_id}. Maybe User was not found!`,
data: null,
});
}
};
This way you have a straight forward code like you usually write when it's synchronous.

Express/Postgres User registration controller

To simplify the situation I'll just post the following controller for an express route which interactions with a Postgres Database. My question is about error handling. If an error occurs it will be caught within the catch clause. But how can I access the errors thrown by the database queries itself. If I make several await several queries and one of them fails I need probably to restore stuff in the database? For example if the insertion of the user in the user table is a success, but the following query of inserting the user in another table fails, I need to delete the user from the user table again. How does one model such flows?
//
// Register User
//
export const registerUser = async (request, response, next) => {
try {
const usersWithSameMail = await client.query(`SELECT * FROM public.users WHERE email = '${user.email}'`);
if(usersWithSameMail.rows.length > 0){
return response.status(403).json({"code": "ERROR", "message": "Email is already registered"})
} else {
await client.query(`
INSERT INTO public.users(first_name, last_name, email, password)
VALUES ('${user.first_name}', '${user.last_name}', '${user.email}', crypt('${user.password}', gen_salt('bf', 8)));
`);
// more await statements...
return response.status(200).json({"code": "INFO", "message": "Verification mail sent to user"});
}
} catch (error) {
return response.status(500).json({"code": "ERROR", "message": "Error occured while registering the user. Please try again."});
}
}```

You can use middlewares chaining your routes handler. In order to it work, you will have to change your current working code to use Single-responsibility principle. Do only one responsability per middleware and chain all handlers to work as one.
Lets say you want to insert new user, to perform this operation we should:
lookup if email is unique
hash password
Insert new user
return inserted data in postgres back as a response
Following the middleware chaining we should implement a function for each action and chain each action in route definition:
const postgres = require('../../lib/postgres');
const crypto = require('crypto');
exports.insertedData = (req, res) => {
res.status(200).json(req.employee);
};
exports.hashPassword = (req, res, next) => {
crypto.scrypt(req.body.password.toString(), 'salt', 256, (err, derivedKey) => {
if (err) {
return res.status(500).json({ errors: [{ location: req.path, msg: 'Could not hash password'}] });
}
req.body.kdfResult = derivedKey.toString('hex');
next();
});
};
exports.lookupEmailUnique = (req, res, next) => {
const sql = 'SELECT e.email FROM public.users e WHERE e.email=$1';
postgres.query(sql, [req.body.email], (err, result) => {
if (err) {
return res.status(500).json({ errors: [{ location: req.path, msg: 'Could not query database' }] });
}
if (result.rows.length > 0) {
return response.status(403).json({"code": "ERROR", "message": "Email is already registered"})
}
next()
});
}
exports.insertNewUser = (req, res, next) => {
const sql = 'INSERT INTO public.users(first_name, last_name, email, password) VALUES ($1,$2,$3,$4} RETURNING *';
postgres.query(sql, [req.body.first_name, req.body.last_name, req.body.email, req.body.kdfResult], (err, result) => {
if (err) {
return res.status(500).json({ errors: [{ location: req.path, msg: 'Could not query database'}] });
}
req.employee = result.rows[0];
next();
});
};
here is your route declaration:
const router = require('express').Router();
const userService = require('../controllers/user.controller');
router.post('/register', userService.lookupEmailUnique, userService.hashPassword, userService.insertNewUser, userService.insertedData);
module.exports = router;
Here in routes you are using the middeware to do the chaning, you only pass the control to next middleware if all conditions are met and has full control from database erros.
In my example I do not used the async/await but I can change my example to have a version using async/await.
example middleware with transaction
exports.deletePostagem = async (req, res, next) => {
try {
await postgres.query('BEGIN');
const sql2 = 'UPDATE comentario SET postagem = null WHERE postagem = $1';
await postgres.query(sql2, [req.params.id]);
const sql3 = 'DELETE FROM postagem WHERE id = $1';
await postgres.query(sql3, [req.params.id]);
await postgres.query('COMMIT');
res.status(204).json();
res.end();
} catch (err) {
await postgres.query('ROLLBACK');
return res.status(500).json({ errors: [{msg: 'Could not perform operation' }]})
}
}
I used this only as an example, but in my projects I always have a middeware for validate/sanitize the data that comes in request before using in database query prepared statements.

based on transaction documentation in node.js you can use rollback
export const registerUser = async (request, response, next) => {
try {
let error = null;
const client; // create a client, connect to the db
try {
await client.query("begin");
await client.query("first query");
await client.query("second query");
await client.query("third query");
await client.query("commit"); //do commit when is finished all queries
} catch (error) {
error = error;
await client.query("rollback");
} finally {
client.release(); // close the connection
}
if (error) {
return response.status(500).json({ message: error }); // error message
}
return response.status(200).json({ message: "My message" }); // success message
} catch (err) {
return response.status(500).json({ message: err });
}
}

Separating Mongoose code from Express Router

So basically, I'm trying to separate my code that handles data (mongoose) from my express Router code, since I might want to use it elsewhere too.
The first thing I did was, I got rid of the res.json() calls, since I don't want the code to only work returning a http response. I want it to return data, so I can then return that data from my router as a http response, but still use it as regular data elsewhere.
Here is a function I wrote to get data from mongoose.
module.exports.user_login = data => {
console.log(data);
ModelUser.findOne({email: data.email}).then(user => {
if(!user){
console.log({email: 'E-mail address not found'});
return {
status: response_code.HTTP_404,
response: {email: 'E-mail address not found'}
}
}
bcrypt.compare(data.password, user.password).then(isMatch => {
if(!isMatch){
console.log({password: 'Invalid password'});
return {
status: response_code.HTTP_400,
response: {password: 'Invalid password'}
}
}
const payload = {
id: user.id,
email: user.email
};
jwt.sign(
payload,
config.PASSPORT_SECRET,
{
expiresIn: "1h"
},
(err, token) => {
console.log({
status: response_code.HTTP_200,
response: {
success: true,
token: token
}
});
return {
status: response_code.HTTP_200,
response: {
success: true,
token: token
}
}
}
);
});
});
};
When this code gets executed in my route like so:
router.post("/login", (req, res) => {
const { errors, isValid } = validateLogin(req.body);
if(!isValid) return res.status(400).json(errors);
console.log("ret", dm_user.user_login(req.body));
});
The log says the return value of user_login() is undefined, even though right before the return statement in user_login() I am logging the exact same values and they are getting logged.
Before I changed it to a log, I tried to store the return value in a variable, but obviously that remained undefined as well, and I got the error: 'Cannot read propery 'status' of undefined' when trying to use the value.
I am definitely missing something..

Well you have an small callback hell here. It might be a good idea to go with async / await and splitting up your code into smaller chunks instead of putting everyhing in 1 file.
I rewrote your user_login function:
const { generateToken } = require("./token.js");
module.exports.user_login = async data => {
let user = await ModelUser.findOne({ email: data.email });
if (!user) {
console.log({ email: "E-mail address not found" });
return {
status: response_code.HTTP_404,
response: { email: "E-mail address not found" }
};
}
let isMatch = await bcrypt.compare(data.password, user.password);
if (!isMatch) {
console.log({ password: "Invalid password" });
return {
status: response_code.HTTP_400,
response: { password: "Invalid password" }
};
}
const payload = {
id: user.id,
email: user.email
};
let response = await generateToken(
payload,
config.PASSPORT_SECRET,
response_code
);
return response;
};
I have moved your token signing method into another file and promisfied it:
module.exports.generateToken = (payload, secret, response_code) => {
return new Promise((res, rej) => {
jwt.sign(
payload,
secret,
{
expiresIn: "1h"
},
(err, token) => {
if (err) {
rej(err);
}
res({
status: response_code.HTTP_200,
response: {
success: true,
token: token
}
});
}
);
});
};
Now you need to change your router function into an async:
router.post("/login", async (req, res) => {
const { errors, isValid } = validateLogin(req.body);
if(!isValid) return res.status(400).json(errors);
let result = await dm_user.user_login(req.body);
console.log(result);
});
In addition: You get undefined because you return your value to an callback function
I also would seperate your routes from your controllers instead of writing your code inside an anonymous function

Please notice that whenever you are trying to return any value you are always present in the callback function and that is definitely not going to return any value to its intended place.
There are a couple of things you can improve about your code :
1.Donot use jwt inside your code where you are making database calls, instead move it where your routes are defined or make a separate file.
2.If you are intending to re-use the code, I would suggest you either use async-await as shown in the answer above by Ifaruki or you can use something like async.js. But the above shown approach is better.
Also always use 'error' field when you are making db calls like this:
ModelUser.findOne({email: data.email}).then((error,user) => {

How do I add an object to a database in Knex where the object is the child of two parents?

I have the code below. Its a standard blog type of setup with users which have posts and comments. Comments are the child of both users and post . Posts belong just to users. Im having a problem posting to comments table. IM not getting any errors when using the insert function , however, when I post a comment to the database nothing gets saved to the comments table . If i do a request to retrieve the comments table , the table still shows empty. What am i doing wrong here .
server.post("/users/:id/posts/:id2/comments", async (req, res) => {
const userID = req.params.id;
const postID = req.params.id2;
db("users")
.where({ id: Number(userID)})
.then((user) => {
db('posts') .where({ id: Number(postID)})
.then((post) => {
//verify if post and user exists
if (post && user) {
req.body.content ? insertComment({
content: req.body.content,
user: userID,
post: postID
})
.then(
res.status(201).json(req.body)
)
.catch((err) => {
console.log(err);
})
: res.status(400).json({
errorMessage: "Please insert text .",
});
} else {
res.status(404).json({
message: "user not found",
});
}
})
})
.catch((err) => {
res.status(500).json({
err,
message: "Error processing request",
});
});
});
function insertComment(comment) {
return db("comments").insert(comment).where({
user: comment.user,
post: comment.post
});
}

since you're already using async function i'd first recommend to use async/await, second notice is that knex returns an array and not an object for example
db("users")
.where({ id: Number(userID)})
.then((user) => {
// user is an array
});
you can chain a query with .first() to retrieve the first object and not an array
Reference from knex documentation
using async/await could save you from callback hell
server.post("/users/:id/posts/:id2/comments", async (req, res) => {
const userID = req.params.id;
const postID = req.params.id2;
try {
const user = await db("users").where("id", Number(userID)).first();
const post = await db("posts").where("id", Number(postID)).first();
if (post && user) {
if (req.body.content) {
await insertComment({
content: req.body.content,
user: userID,
post: postID,
});
return res.status(201).json(req.body);
} else {
return res.status(400).json({
errorMessage: "Please insert text .",
});
}
} else {
return res.status(404).json({
message: "user or post not found",
});
}
} catch (err) {
return res.status(500).json({
err,
message: "Error processing request",
});
}
});
async function insertComment(comment) {
return db("comments").insert(comment).where({
user: comment.user,
post: comment.post,
});
}
and if you have lots of relationships in your application you might find it useful if you want to use an ORM like Objection as it is built on knex.

What is the criteria for extracting code into mongoose methods?

Let's say that I have a model called User which is self-explanatory. Our model has a field called contacts which holds a list of contact IDs. Now for adding a contact, one can use this express route:
router.post("/contacts/add", async (request, response) => {
try {
let user = await User.findOne({
sessionSecret: request.body.claimedSessionSecret,
});
if (!user) {
return response.json({ result: false, error: "An error occured." });
}
let contact = await User.findOne({ email: request.body.email });
if (!contact) {
return response.json({ result: false, error: "User not found." });
}
user.contacts.push(contact._id);
await user.save();
return response.json({ result: true });
} catch (e) {
debug(e);
response.json({ result: false, error: "An error occured." });
}
});
The other choice will be extracting the meat of this route into a static method of our User model and then using that instead. Like this:
// in routes
router.post("/contacts/add", async (request, response) => {
try {
const isContactAdded = await User.addContact(userID, contactID);
return response.json({ result: true });
} catch (e) {
debug(e);
response.json({ result: false, error: "An error occured." });
}
)};
// in model
UserSchema.statics.addContact = async function(userID, contactID) {
...
};
Now the question is which approach is a better code design and why?
Should I extract it into a User's method just because I am modifying the data or should that happen only if the statements are too many?
Since we are able to use functions like save() and findOne() only after creating an instance of the model, shouldn't we be updating the DB the same way that I did above (first approach)? Because otherwise, we would have lots of static methods on our model.