It returns all the rows for which there is at least one match in BOTH the tables. If join type is not specifically mentioned then “INNER JOIN” works as the default join.
INNER JOIN Syntax
SELECT column_name(s)
FROM table1
INNER JOIN table2
ON table1.column_name=table2.column_name;
Example of INNER JOIN
Customer Table
+------------+--------------+------------+------------+--------+------------+-----------+
| CustomerID | CustomerName | ContactNo | Address | CityID | PostalCode | CountryID |
+------------+--------------+------------+------------+--------+------------+-----------+
| 1 | Tarun | 9999075499 | Madan Puri | 124 | 122001 | 91 |
| 2 | Ram | 9650423377 | A-487 | 11 | 110085 | 91 |
| 3 | Sham | 1111111111 | A-485 | 11 | 110085 | 91 |
| 4 | Mohan | 1234567890 | 454 | 124 | 122002 | 91 |
+------------+--------------+------------+------------+--------+------------+-----------+
Order Table
+---------+------------+---------------------+-----------+
| OrderID | CustomerID | OrderDate | ShipperID |
+---------+------------+---------------------+-----------+
| 1 | 1 | 2019-10-02 21:23:12 | 11 |
| 2 | 3 | 2019-10-02 21:23:27 | 12 |
| 3 | 5 | 2019-10-02 21:39:21 | 12 |
+---------+------------+---------------------+-----------+
INNER JOIN Query
use Shopping;
SELECT C.CustomerName, O.OrderID
FROM Customer C
INNER JOIN Orders O
ON C.CustomerID = O.CustomerID
ORDER BY C.CustomerName;
Output
+--------------+---------+
| CustomerName | OrderID |
+--------------+---------+
| Sham | 2 |
| Tarun | 1 |
+--------------+---------+