While MySQL doesn’t directly support FULL JOIN, you can simulate it by combining LEFT JOIN and RIGHT JOIN with a UNION:
SELECT columns
FROM table1
LEFT JOIN table2 ON table1.column = table2.column
UNION
SELECT columns
FROM table1
RIGHT JOIN table2 ON table1.column = table2.column;
table1, table2: The two tables to join.column: The column(s) used to match rows in both tables.Let’s assume we have two tables: employees and departments. We want to retrieve all employees and departments, including those without matches. Here’s the simulated FULL JOIN:
SELECT employees.name, departments.department_name
FROM employees
LEFT JOIN departments ON employees.department_id = departments.id
UNION
SELECT employees.name, departments.department_name
FROM employees
RIGHT JOIN departments ON employees.department_id = departments.id;
In this example:
LEFT JOIN retrieves all employees and their corresponding departments.RIGHT JOIN retrieves all departments and their corresponding employees.UNION ensures that both sets of results are combined, with no duplicates.NULL for non-matching rows.FULL JOIN, it can be simulated using LEFT JOIN and RIGHT JOIN with UNION.Although MySQL does not directly support FULL JOIN, you can simulate this functionality using LEFT JOIN and RIGHT JOIN. A FULL JOIN is useful when you want to combine all rows from both tables, even when some rows do not have matching values in the other table. Understanding how to simulate a FULL JOIN helps you retrieve comprehensive data from multiple tables.