SQL FULL JOIN Keyword
The FULL JOIN keyword return rows when there is a match in one of the tables.
SQL FULL JOIN Syntax
SELECT column_name(s) FROM table_name1 FULL JOIN table_name2 ON table_name1.column_name=table_name2.column_name |
SQL FULL JOIN Example
The "Persons" table:
P_Id | LastName | FirstName | Address | City |
---|---|---|---|---|
1 | Hansen | Ola | Timoteivn 10 | Sandnes |
2 | Svendson | Tove | Borgvn 23 | Sandnes |
3 | Pettersen | Kari | Storgt 20 | Stavanger |
The "Orders" table:
O_Id | OrderNo | P_Id |
---|---|---|
1 | 77895 | 3 |
2 | 44678 | 3 |
3 | 22456 | 1 |
4 | 24562 | 1 |
5 | 34764 | 15 |
Now we want to list all the persons and their orders, and all the orders with their persons.
We use the following SELECT statement:
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons FULL JOIN Orders ON Persons.P_Id=Orders.P_Id ORDER BY Persons.LastName |
The result-set will look like this:
LastName | FirstName | OrderNo |
---|---|---|
Hansen | Ola | 22456 |
Hansen | Ola | 24562 |
Pettersen | Kari | 77895 |
Pettersen | Kari | 44678 |
Svendson | Tove | |
34764 |
The FULL JOIN keyword returns all the rows from the left table (Persons), and all the rows from the right table (Orders). If there are rows in "Persons" that do not have matches in "Orders", or if there are rows in "Orders" that do not have matches in "Persons", those rows will be listed as well.
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