Contents
SQL INNER JOIN Keyword: Main Tips
- The INNER JOIN keyword selects the pair tables rows if there is a match between in two tables columns.
- INNER JOIN acts the same as JOIN.
Syntax of SQL INNER JOIN
Selects information that has matching values in both tables.
Example
SELECT column_name(s)
FROM mytable1
INNER JOIN mytable2 ON mytable1.column_name = mytable2.column_name;Demo Database
This is demo example from the "Developers" table in the database:
| ID | Name | City | Country |
|---|---|---|---|
| 1 | Tom Kurkutis | New York | USA |
| 2 | Ana Fernandez | London | UK |
| 3 | Antonio Indigo | Paris | France |
| 4 | Aarav Kaelin | Delhi | India |
| 5 | Andrew Tumota | Miami | USA |
This is demo example from the "Orders" table in the database:
| ID | Customer_ID | Employee_ID |
|---|---|---|
| 20408 | 2 | 7 |
| 20409 | 2 | 5 |
| 85471 | 1 | 3 |
| 75864 | 5 | 8 |
SQL INNER JOIN: Examples
The next SQL statement will return all developers with orders:
Example
SELECT Orders.ID, Developers.Name
FROM Orders
INNER JOIN Developers ON Orders.ID = Developers.ID;Note: the columns are matching, the INNER JOIN keyword selects the two tables rows. Customers will NOT be listed, if there is a difference between the rows.
In this example we JOIN three tables: select all orders with developer and client information:
Example
SELECT Orders.ID, Developers.Name, Customers.Name
FROM ((Orders
INNER JOIN Developers ON Orders.ID = Developers.ID)
INNER JOIN Customers ON Orders.ID = Customers.ID);