SQL JOINS:

                SQL joins has five type of  keywords.

namely,

      INNER  JOIN

      OUTER  JOIN

      LEFT  JOIN

      RIGHT  JOIN

      FULL  JOIN

INNER JOIN:

The INNER JOIN keyword return rows when there is at least one match in both tables.

Syntax:

SELECT column_name(s) FROM tablename1 as t1 INNER JOIN tablename2 as t2 ON t1.column_name=t2.column_name

SQL INNER JOIN Example

The table “Customer” is,

Id	Name	Address	City
1	Vaishnavi	10,Anna Nagar	Bangalore
2	Shajil	23,T.Nagar	Chennai
3	Vinoth	20,Sivaji Street	Chennai

The  table “Order” is,

O_Id	OrderNo	Id
1	77895	3
2	44678	3
3	22456	1
4	24562	1
5	34764	15

Query:

SELECT C.Name, C.City, O.OrderNo FROM Customer as C INNER JOIN Orders as O ON C.Id=O.Id

The result-set will be:

Name	City	OrderNo
Vaishnavi	Bangalore	22456
Vaishnavi	Bangalore	24562
Vinoth	Chennai	77895
Vinoth	Chennai	44678

Note that, the INNER JOIN keyword return rows when there is at least one match in both tables. If there are rows in "Customer" that do not have matches in "Orders", those rows will NOT be listed.