SQL Full Join
A SQL Full Join, also known as a Full Outer Join, is a type of join operation that combines the rows from two tables, including matching and non-matching rows from both tables. In other words, it returns all the records from both tables, and if there is no match, NULL values are used to fill in the columns from the non-matching table.
The syntax for a Full Join in SQL varies slightly depending on the database system you are using. Here’s a generic example:
SELECT column1, column2, ... FROM table1 FULL JOIN table2 ON table1.column = table2.column;
In this example,
table2 are the names of the tables you want to join, and
column is the common column between the two tables that you want to match on. The
SELECT statement specifies the columns you want to retrieve from the joined result.
Keep in mind that not all database systems support the Full Join syntax. In some cases, you may need to use a combination of a Left Join and a Right Join to achieve the same result.
Here’s an example using sample tables:
SELECT customers.customer_id, orders.order_id FROM customers FULL JOIN orders ON customers.customer_id = orders.customer_id;
This query retrieves the
customer_id from the
customers table and the
order_id from the
orders table, joining them based on the matching
customer_id column. The result will include all customers and their corresponding orders, and if there is no match, NULL values will be displayed for the non-matching rows.
Note that the syntax and support for Full Joins may vary depending on the specific database management system you are using.