SQL Left Outer Join

The left outer join returns a result table with the matched data of two tables then remaining rows of the lefttable and null for the right table's column.

Left Outer Join syntax is,

SELECT column-name-list
from table-name1 
LEFT OUTER JOIN 
table-name2
on table-name1.column-name = table-name2.column-name;

Left outer Join Syntax for Oracle is,

select column-name-list
from table-name1, 
table-name2
on table-name1.column-name = table-name2.column-name(+);

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Example of Left Outer Join

The class table,

ID	NAME
1	abhi
2	adam
3	alex
4	anu
5	ashish

The class_info table,

ID	Address
1	DELHI
2	MUMBAI
3	CHENNAI
7	NOIDA
8	PANIPAT

Left Outer Join query will be,

SELECT * FROM class LEFT OUTER JOIN class_info ON (class.id=class_info.id);

The result table will look like,

ID	NAME	ID	Address
1	abhi	1	DELHI
2	adam	2	MUMBAI
3	alex	3	CHENNAI
4	anu	null	null
5	ashish	null	null