This join returns all the rows from the right table with the matching rows from the left table. If there are no columns mathcing in the left table ,it returns NULL values.
Use Right Outer Join when you only want to return rows that have matching data in the right table, even if there's no matching rows in the left table.
Ex:
Left Table(emp Table)
------------------------------------------------------------------------
empID FirstName LastName UserName
------------------------------------------------------------------------
1 John Miller John
2 Steve Jobs Steve
3 Billgates john Billgates
4 Ozzy Ozzbourne Ozzy
5 Homer Gain Homer
--------------------------------------------------------------------------
Right Table(dept Table)
------------------------------------------------------
empID DeptName
------------------------------------------------------
1 IT
2 Networking
3 Networking
4 Networking
12 Admin
------------------------------------------------------
Query :
SELECT * FROM emp AS e
RIGHT JOIN dept AS d
ON e.empid = d.empid
result:
empID FirstName LastName UserName IndividualId AccessLevel
1 John Miller John 1 IT
2 Steve Jobs Steve 2 Networking
3 Billgates john Billgates 3 Networking
4 Ozzy Ozzbourne Ozzy 4 Networking
NULL NULL NULL NULL 12 Admin
Use Right Outer Join when you only want to return rows that have matching data in the right table, even if there's no matching rows in the left table.
Ex:
Left Table(emp Table)
------------------------------------------------------------------------
empID FirstName LastName UserName
------------------------------------------------------------------------
1 John Miller John
2 Steve Jobs Steve
3 Billgates john Billgates
4 Ozzy Ozzbourne Ozzy
5 Homer Gain Homer
--------------------------------------------------------------------------
Right Table(dept Table)
------------------------------------------------------
empID DeptName
------------------------------------------------------
1 IT
2 Networking
3 Networking
4 Networking
12 Admin
------------------------------------------------------
Query :
SELECT * FROM emp AS e
RIGHT JOIN dept AS d
ON e.empid = d.empid
result:
empID FirstName LastName UserName IndividualId AccessLevel
1 John Miller John 1 IT
2 Steve Jobs Steve 2 Networking
3 Billgates john Billgates 3 Networking
4 Ozzy Ozzbourne Ozzy 4 Networking
NULL NULL NULL NULL 12 Admin
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