Develop Reference

PostgreSQL query to Supabase Query

How can i make once of this PostgreSQL querys in supabase?
I tried reading supabase doc but it doesn't work
select rooms.id as room_id, members.id as member_id, user_id from rooms
inner join members
on rooms.id = members.room_id
where rooms.id = members.room_id
and user_id = 1
Or
select room_id, user_id, members.id from members
inner join rooms
on rooms.id = members.room_id
where members.user_id = 1

No, there's not really any performance difference from calling an .rpc() vs. just calling the api directly. You should be fine. Just make sure to set up your database correctly (indexes, joins, etc.) for best performance.

Hello this might not be supabase specific solution, but in my case what I do use when I need to run custom queries like in your own case here is to use the pg package from npm https://www.npmjs.com/package/pg.
I would just create a client and parse my supabase db credentials to it.
export const pgClient = () => {
console.error(`using Postgres ${process.env.host}`)
const client = new Client({
user: process.env.user,
host: process.env.host,
database: process.env.database,
password: process.env.password,
port: parseInt(process.env.port!)
})
return client
}
export it to my router and simply connect
const client = pgClient()
await client.connect()
Run my custom query directly on the DB
await client.query("SELECT * from auth.users")

You can query a foreign table using the Supabase client, but only if there's a foreign key set up:
Supabase select(): Query foreign tables
As stated in the comments, you can create a view for this purpose:
Create View
Or you can create a PosgreSQL function and call that with Supabase .rpc():

Is there a way to create a database with mongoose that has a username and password?

I'm currently working on a app (dev with electron). I'm using mongoDB and mongoose for my persistant storage but I can't find a way to do something that seem really basic : when creating a database I'd like to add an user and a password to it (I realy search for it, but no way to find anything usable).
I have this need because it's going to be a multi-user app and I definitly don't want an user to know the contents of another user account.
The idea is that once you create an account, the app create a database that has the same username and password of the account. For login, the app try to connect you to the database with your account & password.
I'm working with :
electron
HTML / CSS / javascript
mongoDB
mongoose
Here is the code that I tested :
var mongoose = require('mongoose');
var connStr = "mongodb://localhost:27017/test";
mongoose.connect(connStr, {user: 'newUser', password: 'pwd', useNewUrlParser: true }, function(err) {
if (err) {throw err};
console.log("Successfully connected to MongoDB");
});
I get the error
Uncaught (in promise) MongoNetworkError: failed to connect to server [localhost:27017] on first connect [MongoError: password must be a string]
However with those, the database is correctly created (but anyone can access it) :
user: '', password: ''
What I expect is to create a new database with the user name set as "newUser" and the password as "pwd", in that way only with the correct id & password would it be possible to connect to it.
Thanks for your help !

I don't know if this will work or not but I ran a mongo service using docker and then connected mongoose to it with the following code
mongoose.connect('mongodb://user:pass#localhost:port/MyDB?authSource=admin', {
useNewUrlParser: true
})
.then(() => console.log('MongoDB connection successful'))
.catch(err => console.error('Could not connect to MongoDB:‌', err));
this is equivalent to
mongo --username user --password pass --authenticationDatabase admin --port 27017

Multiple database switching dynamic in node-express

i have searched lot to get a solution to my problem. but didn't got it.
if anyone have the experience in such situations please help me.
i have created a application server in node express with MySQL a database.
and successfully create REST API endpoints which works successfully.
but our projects scaled up. a new client approaches so we need to serve those clients too.
those client may have 1k users.but the database schema is same.
solution 1: create a separate server and database for each client with different port no.
but i don't think this is good solution because if we have 100 client we can't maintain the code base.
solution 2: create a separate database for each client and switch database connection at run time.
but i don't understand how to implement solution 2. any suggestion highly appreciated.
if more than one client requesting same server how to know which database need to connect using the endpoint URL. i there any alternate way to tackle this situation.
my solution: create a middle ware to find out the which database is required and return the connection string.is it good idea.             
middleware. in below example i use JWT token which contain database name.
const dbHelper=new db();
class DbChooser {
constructor(){
this. db=
{
wesa:{
host: "xxx",
user: "xxxx",
password: "xxxxx",
database: "hdgh",
connectionLimit:10,
connectTimeout:30000,
multipleStatements:true,
charset:"utf8mb4"
},
svn:{
host: "x.x.x.x.",
user: "xxxx",
password: "xxx",
database: "xxx",
connectionLimit:10,
connectTimeout:30000,
multipleStatements:true,
charset:"utf8mb4"
}
};
}
async getConnectiontring(req,res,next){
//console.log(req.decoded);
let d=new DbChooser();
let con=d.db[req.decoded.userId];
console.log(mysql.createPool(con));
next();
}
}
module.exports=DbChooser;

You can create a config JSON. On every request, request header should have a client_id based on the client_id we can get the instance of the database connection.
your db config JSON
var dbconfig = {
'client1': {
databasename: '',
host: '',
password: '',
username: ''
},
'client2': {
databasename: '',
host: '',
password: '',
username: ''
}
}
You should declare a global object, to maintain the singleton db instances for every client.
global.dbinstances = {};
on every request, you are going to check whether the instance is already available in your global object or not. If it's available you can go continue to the next process, otherwise it creates a new instance.
app.use('*', function(req,res) {
let client_id = req.headers.client_id;
if(global.instance[client_id]) {
next();
} else {
const config = dbconfig[client_id];
connectoDb(config, client_id);
}
}
function connectoDb(config, client_id) {
//.. once it is connected
global.instance.push({client_id: con}); //con refers to the db connection instance.
}

Sending data to Database in React.js web application

I'm creating a web application and I'm curious how to send data to MySQL database in it. I have a function that is invoked when user presses button, I want this function somehow to send data to the MySQL server. Does anyone know how to approach this problem? I tried npm MySQL module but it seems the connection doesn't work as it is client side. Is there any other way of doing it? I need an idea to get me started.
Regards

You will need a server that handles requests from your React app and updates the database accordingly. One way would be to use NodeJS, Express and node-mysql as a server:
var mysql = require('mysql');
var express = require('express');
var app = express();
// Set up connection to database.
var connection = mysql.createConnection({
host: 'localhost',
user: 'me',
password: 'secret',
database: 'my_db',
});
// Connect to database.
// connection.connect();
// Listen to POST requests to /users.
app.post('/users', function(req, res) {
// Get sent data.
var user = req.body;
// Do a MySQL query.
var query = connection.query('INSERT INTO users SET ?', user, function(err, result) {
// Neat!
});
res.end('Success');
});
app.listen(3000, function() {
console.log('Example app listening on port 3000!');
});
Then you can use fetch within a React component to do a POST request to the server, somewhat like this:
class Example extends React.Component {
constructor() {
super();
this.state = { user: {} };
this.onSubmit = this.handleSubmit.bind(this);
}
handleSubmit(e) {
e.preventDefault();
var self = this;
// On submit of the form, send a POST request with the data to the server.
fetch('/users', {
method: 'POST',
data: {
name: self.refs.name,
job: self.refs.job
}
})
.then(function(response) {
return response.json()
}).then(function(body) {
console.log(body);
});
}
render() {
return (
<form onSubmit={this.onSubmit}>
<input type="text" placeholder="Name" ref="name"/>
<input type="text" placeholder="Job" ref="job"/>
<input type="submit" />
</form>
);
}
}
Keep in mind that this is only one of infinite ways to achieve this.

It depends on how your application is organized, I will guess that you have a server that provides your React application code.
I would advise you to send the necessary information to your server (if there is any) using a module based on your preferences:
fetch built-in XHR api (https://developer.mozilla.org/en/docs/Web/API/Fetch_API)
request callback-based npm module (https://www.npmjs.com/package/request)
axios promise-based npm module (https://www.npmjs.com/package/axios)
If you are looking for a module/plugin doing all the work from client to database I don't know any and not sure there is because it is usually advised to use a proxy (a server to redirect but also to format or block requests between your client and the database).
Then, in your server you format the necessary information (if any) to be usable by your MySQL database, and then contact your MySQL database with the module of your choice, the first most popular module seems to be:
https://www.npmjs.com/package/mysql, but if you know another one or have other preferences go on. (For example with MongoDB we can use Mongoose to make requests easier)

Send data back to node.js server from front-end

I am new to Node.js and I'm trying to figure out for few days how to make a simple login-register feature for a website using Express.js with EJS template engine and MySql.
I have installed Node on my PC and I've used the Express-Generator to make a basic folder structure (views, routes, public folders).
I understand how I can pass variables from node to the front end using ejs but I don't know how to pass it back. I've tried watching some tutorials on the internet but nothing seems to make me see the logic. Where do I put the MySql code? How can I pass back the input values once the user clicks "SUBMIT"?

How says Jake, I suggest to use Sequelize for MySQL.
I will try to make a small steps for your start, and after you can study more about each process and tool.
1) Front-end (EJS);
<form id="login" action="/login" method="post">
<input name="username" type="text">
<input name="password" type="password">
<input type="submit">Ok</input>
</form>
Here, the form will request the route login. The route:
2) Route
module.exports = function (app){
var login = app.controllers.login;
app.get('/', login.index);
app.post('/login', login.login)
};
The route will call the login method in the controller called login.js.
3) Controller
module.exports = function(app) {
var sequelize = require('./../libs/pg_db_connect'); // resquest lib of connection to mysql/postgres
var LoginController = {
index: function(req, res) {
res.render('login/index');
},
login: function(req, res) {
var query = "SELECT * FROM users"; // query for valid login
sequelize.query(query, { type: sequelize.QueryTypes.SELECT}).then(function(user){
if (req.body.username == user[0].username && req.body.password === user[0].password ){
res.redirect("/home");
} else {
res.render("login/invalid_access");
}
});
}
};
return LoginController;
};
In this point, is exec the query for to valid the login and verify if user can be log in. Request method is the main point.
For response and send information to view, it used res.SOME_METHOD:
res.send();
res.end();
res.download();
res.json();
Plus: Sequelize MySQL connection.
In the express structure, it's localized in lib/my_db_connection.js:
var Sequelize = require('sequelize');
module.exports = new Sequelize('database_name', 'user', 'pass', {
host: 'localhost',
dialect: 'mysql',
pool: {
max: 10,
min: 0,
idle: 10000
},
});
I suggest before you code, read the necessary docs.

You're going to have to use some sort of AJAX library (or vanilla js ajax) to send the information to a http endpoint you set up in express. For simple stuff the jquery ajax methods will do just fine. You will likely are looking to make a POST request.
As for the MySql code, checkout Sequelize. Its a cool library for interacting with sql databases from express. Its similar to how mongoose works for mongo.