How to insert some table information to another table column? - mysql

Question

I am a beginner in mySQL and I am trying to create a user's table with information about the user (see code) and populate a column with details that I get from a new table that gets created.
Now I want to be able to put some information from the 'creditcards' table like number for example, to the 'users' table which includes a column 'creditcard', so that I can see each user's credit card number.
I am also comparing the name of the user with the name of the credit card owner so it populates the table according to the user.
I couldn't find any information about the specific problem I am having here.
Here's how I am trying to write:
con.query(createNewCreditCard, [name, type, number, expiration, svss], (err, results) => {
if (err) {
console.error(err);
} else {
const JoinCreditCard = 'INSERT INTO users (creditcard) SELECT number,name FROM creditcards WHERE users.name = creditcards.name';
const userCreateModel = `
CREATE TABLE IF NOT EXISTS users (
id INT(11) NOT NULL AUTO_INCREMENT,
name VARCHAR(45) NOT NULL,
username VARCHAR(45) NOT NULL,
email VARCHAR(45) NOT NULL,
phonenumber VARCHAR(45) NOT NULL,
password VARCHAR(255) NOT NULL,
creditcard INT(11),
salt VARCHAR(255),
created_at DATE,
update_at DATE,
deleted_at DATE,
lastSignIn DATE,
PRIMARY key (id)
)
`;
const CreditCardModel = `
CREATE TABLE IF NOT EXISTS creditcards (
id INT(11) NOT NULL AUTO_INCREMENT,
name VARCHAR (25) NOT NULL,
type VARCHAR(10) NOT NULL,
number INT(12) NOT NULL,
expiration DATE,
svss INT(3) NOT NULL,
created_at DATE,
PRIMARY key (id)
)
`;
I am trying to create a user named ula and then a credit card with the name ula (and all other columns) which I am sending from postman.
The credit card part in nodejs looks like this:
const createCreditCard = async (req, res, next) => {
const {
name,
type,
number,
expiration,
svss
}: {
name: String,
type: String,
number: String,
expiration: String,
svss: String
} = req.body;
const createAt = new Date(Date.now());
try {
const createNewCreditCard = 'INSERT INTO creditcards (name, type, number, expiration, svss) VALUES (?,?,?,?,?)';
con.query(createNewCreditCard, [name, type, number, expiration, svss], (err, results) => {
if (err) {
console.error(err);
} else {
const JoinCreditCard = 'UPDATE users SET creditcard=' + number + ' WHERE name="' + name + '"';
console.log(results);
}
});
res.status(201).send({ success: true, message: 'New credit card was created', data: {name, type, number, expiration, svss} });
} catch (error) {
res.status(500).send({ success: false, message: 'Server error' });
}
await next;
}
The server returns 201, I go to mysql, open users, see column creditcard and its NULL.

Answer 1

Because the entry already exists in the database for users table, you should use UPDATE instead of INSERT.
An example that should work with your code (you already know name and number as vars because you just created the credit card info with them, no need to select them again):
con.query(createNewCreditCard, [name, type, number, expiration, svss], (err, results) => {
if (err) {
console.error(err);
} else {
const JoinCreditCard = 'UPDATE users SET creditcard=' + number + ' WHERE name="' + name + '"';
EDIT: this is the new code from your edit. You already use prepared statements, so forget my notice about that. I've updated the query to follow this. What was missing in your code is that you need to actually do the query! Only declaring the constant won't do anything to your database..
try {
const createNewCreditCard = 'INSERT INTO creditcards (name, type, number, expiration, svss) VALUES (?,?,?,?,?)';
con.query(createNewCreditCard, [name, type, number, expiration, svss], (err, results) => {
if (err) {
console.error(err);
} else {
console.log(results);
const JoinCreditCard = 'UPDATE users SET creditcard=? WHERE name=?';
con.query(JoinCreditCard, [number, name], (err, results) => {
if (err) {
console.error(err);
} else {
console.log(results);
}
});
}
});
res.status(201).send({ success: true, message: 'New credit card was created', data: {name, type, number, expiration, svss} });
} catch (error) {
res.status(500).send({ success: false, message: 'Server error' });
}
NOTE: you should know that using the name to reference the credit card will not allow you to have multiple credit cards for one user, and should be careful about users with the same name, or else this query will update both users. It would be safer to always use the user id field in the WHERE clause. (you should know it at this point)
THIS IS WHAT I RECOMMEND:
it's usually better that the creditcard in users only stores the id from the creditcards table. Like this, relations are on the primary key and it's more optimized (you need to get the id after the credit card creation request, in an inner SELECT in following code).
use the ids to identify rows updates, to prevent 2 users to be updated
delete name from creditcards table, it's already in users
having a third table to reference the relations like states user1974729 is not mandatory, however, it will be the case if you conveniently want to be able to have more than one credit card per user or more than one user that share a card (1 to n relation)
code:
//relation based on id instead of number stored in users + name removed. I assume at this point, you know the id of your user (in var "id" used below in `WHERE` clause)
con.query(createNewCreditCard, [type, number, expiration, svss], (err, results) => {
if (err) {
console.error(err);
} else {
const JoinCreditCard = 'UPDATE users SET creditcard=(SELECT id FROM creditcards WHERE type="' + type + '" AND number="' + number + '" AND expiration="' + expiration + '" AND svss="' + svss + '") WHERE id="' + id + '"';
//no change in userCreateModel
//deleted "name" in CreditCardModel
const CreditCardModel = `
CREATE TABLE IF NOT EXISTS creditcards (
id INT(11) NOT NULL AUTO_INCREMENT,
type VARCHAR(10) NOT NULL,
number INT(12) NOT NULL,
expiration DATE,
svss INT(3) NOT NULL,
created_at DATE,
PRIMARY key (id)
)
`;

Answer 2

it is important that the tables are in normalized forms.
There should be 3 tables.
Users -- all the user data
Credit cards -- all the credit card related information.
Users credit card map -- map users to credit card information.