How can you perform right join on two tables using MySQL in Python?

PythonServer Side ProgrammingProgramming

We can join two tables in SQL based on a common column between them or based on some specified condition. There are different types of JOIN available to join two SQL tables.

Here, we will discuss about the RIGHT join on two tables.In the RIGHT JOIN, all the records from the second table or the right table are always included in the result. From the left table, the matching records are joined to the records of the right table. If there is no matching record found for a row in right table, then None is joined with that record.

The tables are joined on basis of some condition. But all the records of the right table will always be included in the result irrespective of the condition.

Syntax

SELECT column1, column2...
FROM table_1
RIGHT JOIN table_2 ON condition;

Let there be two tables, “Students” and “Department” as folllows −

Students

+----------+--------------+-----------+
|    id    | Student_name | Dept_id   |
+----------+--------------+-----------+
|    1     |    Rahul     |    120    |
|    2     |    Rohit     |    121    |
|    3     |    Kirat     |    121    |
|    4     |    Inder     |    123    |
+----------+--------------+-----------+

Department

+----------+-----------------+
| Dept_id  | Department_name |
+----------+-----------------+
|    120   |    CSE          |
|    121   |    Mathematics  |
|    122   |    Physics      |
+----------+-----------------+

We will perform right join on the above tables based on the dept_id which is common in both the tables.

Steps to perform right join on two tables using MySQL in python

  • import MySQL connector

  • establish connection with the connector using connect()

  • create the cursor object using cursor() method

  • create a query using the appropriate mysql statements

  • execute the SQL query using execute() method

  • close the connection

Example

import mysql.connector
db=mysql.connector.connect(host="your host", user="your username", password="yourpassword",database="database_name")

cursor=db.cursor()
query="SELECT Students.Id,Students.Student_name,Department.Department_name
FROM Students RIGHT JOIN Department ON Students.Dept_Id=Department.Dept_Id"
cursor.execute(query)
rows=cursor.fetchall()
for x in rows:
   print(x)

db.close()

Output

(1, ‘Rahul’, ‘CSE’)
(2, ‘Rohit’, ‘Mathematics’)
(3, ‘Kirat’ , ‘Mathematics’)
(None, ‘Physics’)

Notice, all the records from the right table are included in the result even though there are no matching records for the last row.

raja
Published on 10-Jun-2021 12:51:14
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