Full outer join

Full outer join returns all the rows from both tables whether it has been matched or not.The FULL OUTER JOIN keyword combines the result of both LEFT and RIGHT joins. 

Syntax:

SELECT
column_name(s)
FROM Table1 (Left Side Table)
FULL JOIN Table2 (Right Side Table)
ON table1.column_name=table2.column_name
 
or:
 
SELECT
column_name(s)
FROM Table1 (Left Side Table)
FULL OUTER JOIN Table2 (Right Side Table)
ON table1.column_name=table2.column_name

Example:

SELECT ProductName AS [Product Name]
,UnitPrice AS [Price]
,CategoryName AS [Product Category],ImagePath AS [Image]
 FROM Products P
FULL OUTER JOIN Categories C ON P.CategoryID=C.CategoryID

Full join t-sql query will return result