Structured query language full join

FULL JOIN : 

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.