A MySQL left join and a right join are both used to combine rows from two or more tables, based on a related column between them. The main difference between the two joins is the inclusion of non-matched rows. The LEFT JOIN includes all records from the left side and matched rows from the right table, whereas RIGHT JOIN returns all rows from the right side and unmatched rows from the left table.
The syntax of a MySQL left join query is as follows:
SELECT column_list
FROM table_name1
LEFT JOIN table_name2
ON table_name1.column_name = table_name2.column_name;
The column_list is a list of columns that you want to retrieve. You can specify all columns by using the asterisk (*), or you can specify specific columns.
The table_name1 and table_name2 are the names of the tables that you want to join.
The LEFT keyword specifies that you want to perform a left join.
The ON clause specifies the join condition.
For example, the following query will return all rows from the users table, and the matched rows from the orders table:
SELECT *
FROM users
LEFT JOIN orders
ON users.id = orders.user_id;
This query will return all rows from the users table, even if there are no matching rows in the orders table. For any rows in the users table that do not have a matching row in the orders table, the columns from the orders table will be NULL.
The syntax of a MySQL right join query is as follows:
SELECT column_list
FROM table_name1
RIGHT JOIN table_name2
ON table_name1.column_name = table_name2.column_name;
The column_list is a list of columns that you want to retrieve. You can specify all columns by using the asterisk (*), or you can specify specific columns.
The table_name1 and table_name2 are the names of the tables that you want to join.
The RIGHT keyword specifies that you want to perform a right join.
The ON clause specifies the join condition.
For example, the following query will return all rows from the orders table, and the matched rows from the users table:
SELECT *
FROM orders
RIGHT JOIN users
ON users.id = orders.user_id;
This query will return all rows from the orders table, even if there are no matching rows in the users table. For any rows in the orders table that do not have a matching row in the users table, the columns from the users table will be NULL.
I hope this helps! Let me know if you have any other questions