MySQL Joins Tutorial; Through this tutorial, i am going to show you types of joins in mysql and how to use MySQL JOINS with the help of examples.
MySQL JOINS are used to retrieve data from multiple tables. A MySQL JOIN is performed whenever two or more tables are joined in a SQL statement.
MySQL JOINS Tutorial – INNER, OUTER, LEFT, RIGHT, CROSS
There are four types of joins in MySQL; as follows:
- INNER JOIN MySQL
- LEFT JOIN MySQL
- RIGHT JOIN MySQL
- SELF JOIN MySQL
MySQL INNER JOIN
MySQL INNER JOIN clause selects records if the given column values matching in both tables. MySQL INNER JOIN is used to fetch data from multiple tables.
Syntax of MySQL INNER JOIN
SELECT table1.column, table2.column
FROM table1
INNER JOIN table2
ON table1.column = table2.column;
Example of MySQL INNER JOIN
See the mysql inner join example; as follows:
SELECT city, country FROM city INNER JOIN country ON city.country_id = country.country_id;
MySQL LEFT JOIN
The MySQL LEFT JOIN clause returns all rows from the left table, even if there are no matches in the right table, The result is NULL from the right side.
Syntax of MySQL LEFT JOIN
SELECT column_name(s)
FROM table1
LEFT JOIN table2
ON table1.column_name = table2.column_name;
Example of MySQL LEFT JOIN
See the mysql left join example; as follows:
SELECT u.user_id, u.first_name, u.last_name, a.autor_id, a.first_name, a.last_name FROM users u LEFT JOIN actor a ON u.last_name = a.last_name ORDER BY u.last_name;
MySQL Right JOIN
The MySQL Right JOIN clause returns all rows from the right table, even if there are no matches in the right table, The result is NULL from the right side.
Syntax of MySQL Right JOIN
SELECT column_name(s)
FROM table1
Right JOIN table2
ON table1.column_name = table2.column_name;
Example of MySQL Right JOIN
See the mysql right join example; as follows:
SELECT u.user_id, u.first_name, u.last_name, a.autor_id, a.first_name, a.last_name FROM users u RIGHT JOIN actor a ON u.last_name = a.last_name ORDER BY a.last_name;
MySQL Self Join
The MySQL self join is used to join a table to itself when using a join clause.
MySQL self join is useful when you want to combine the records in a table with other records in the same table.
Example of MySQL Self Join
SELECT a.customer_id, a.first_name, a.last_name, b.customer_id, b.first_name, b.last_name FROM customer a INNER JOIN customer b ON a.last_name = b.first_name;
Conclusion
MySQL Joins tutorial, you have learned how to many types of joins in mysql and how to use mysql joins with the help of examples.
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