The right way to Be a part of A number of MySQL Tables in Python

First, you will want the mysql.connector. In case you are uncertain of tips on how to get this setup, discuss with The right way to Set up MySQL Driver in Python.

Presenting the info

let’s take two (2) tables as an indication for the code beneath.

Customers – Desk 1

{ id: 1, title: 'Carl', fav: 254},
{ id: 2, title: 'Emma', fav: 254},
{ id: 3, title: 'John', fav: 255},
{ id: 4, title: 'Hayley', fav:},
{ id: 5, title: 'Andrew', fav:}

Merchandise – Desk 2

{ id: 254, title: 'Chocolate Chip Cookie Dough' },
{ id: 255, title: 'Buttered Pecan' },
{ id: 256, title: 'Cookies & Cream' }

These two tables may be mixed by utilizing customers’ fav subject and merchandise’ id subject.

The right way to Be a part of A number of MySQL Tables collectively in Python

import mysql.connector

mydb = mysql.connector.join(
  host = "localhost",
  consumer = "username",
  password = "YoUrPaSsWoRd",
  database = "your_database"
)

mycursor = mydb.cursor()

sql = "SELECT 
  customers.title AS consumer, 
  merchandise.title AS favourite 
  FROM customers 
  INNER JOIN merchandise ON customers.fav = merchandise.id"

mycursor.execute(sql)

myresult = mycursor.fetchall()

for x in myresult:
  print(x)

Within the instance above, Hayley, and Andrew had been excluded from the outcome, that’s as a result of INNER JOIN solely exhibits the data the place there’s a match.

What’s a Left Take part MySQL

If you wish to present all customers, even when they don’t have a favourite product, use the LEFT JOIN assertion:

sql = "SELECT 
  customers.title AS consumer, 
  merchandise.title AS favourite 
  FROM customers 
  LEFT JOIN merchandise ON customers.fav = merchandise.id"

What’s a Proper Take part MySQL

If you wish to return all merchandise, and the customers who’ve them as their favourite, even when no consumer has them as their favourite, use the RIGHT JOIN assertion:

sql = "SELECT 
  customers.title AS consumer, 
  merchandise.title AS favourite 
  FROM customers 
  RIGHT JOIN merchandise ON customers.fav = merchandise.id"