SQL OUTER JOIN

When we want to select out all the record from two table, no matter it's present at second table or not, we will have to use SQL OUTER JOIN command.

There are 3 type of OUTER JOIN, which is:
LEFT OUTER JOIN
RIGHT OUTER JOIN
FULL OUTER JOIN

SQL OUTER JOIN syntax:

SELECT *
FROM [TABLE 1] OUTER JOIN [TABLE 2]
ON [TABLE 1].[COLUMN NAME 1] = [TABLE 2].[COLUMN NAME 2]

EXAMPLE :

Let's say we got 2 tables containt data like Below:

Table 1: GameScores

PlayerName	DepartmentId	Scores
Jason	1	3000
Irene	1	1500
Jane	2	1000
David	2	2500
Paul	3	2000
James	4	2000

Table 2: Departments

DepartmentId	DepartmentName
1	IT
2	Marketing
3	HR
5	QA

LEFT OUTER JOIN will return all records from the first table,
SQL statement and Result for LEFT OUTER JOIN is :

SELECT * FROM GameScores2
LEFT OUTER JOIN Departments
ON GameScores2.DepartmentId = Departments.DepartmentId

Result:

PlayerName	DepartmentId	Scores	DepartmentId	DepartmentName
Jason	1	3000	1	IT
Irene	1	3000	1	IT
Jane	2	3000	2	Marketing
David	2	3000	2	Marketing
Paul	3	3000	3	HR
James	4	2000	NULL	NULL

RIGHT OUTER JOIN will return all records from the second table,
SQL statement and Result for RIGHT OUTER JOIN is :

SELECT * FROM GameScores2
RIGHT OUTER JOIN Departments
ON GameScores2.DepartmentId = Departments.DepartmentId

Result:

PlayerName	DepartmentId	Scores	DepartmentId	DepartmentName
Jason	1	3000	1	IT
Irene	1	3000	1	IT
Jane	2	3000	2	Marketing
David	2	3000	2	Marketing
Paul	3	3000	3	HR
NULL	NULL	NULL	5	QA

FULL OUTER JOIN will return all records from all tables,
SQL statement and Result for FULL OUTER JOIN is :

SELECT * FROM GameScores2
FULL OUTER JOIN Departments
ON GameScores2.DepartmentId = Departments.DepartmentId

Result:

PlayerName	DepartmentId	Scores	DepartmentId	DepartmentName
Jason	1	3000	1	IT
Irene	1	3000	1	IT
Jane	2	3000	2	Marketing
David	2	3000	2	Marketing
Paul	3	3000	3	HR
James	4	2000	NULL	NULL
NULL	NULL	NULL	5	QA