How to JOIN 3 tables or more

Join 3 tables (or more) syntax

SELECT t1.column_1, t2.column_2, t3. column_3..., tx.column_x
FROM table_1 t1, table_2 t2, table_3 t3, ..., table_x tx
WHERE t1.column_1 = t2.column_2
AND t2.column_2 = t3.column_3
...
AND t(x-1).column_(x-1) = tx.column_x;

Ofcourse, there is no need to keep column’s indexes ordered like in the syntax above. They just have to store the same type’s of values to match to each other in the same way we used it with basic JOIN statement.

Let’s take a closer look at the sample tables: PILOTS, AIRCRAFTS and AIRPORTS.

SELECT * FROM pilots;

SELECT * FROM aircrafts;

SELECT * FROM airports;

in this case, each table has a common collumn “location”. This is our key for joining tables.
We are looking for the plane and pilot who works at specific airport which has a fuel station.

SELECT name, aircraft, pilots.location, fuel_station
FROM pilots, aircrafts, airports
WHERE pilots.location = aircrafts.location
AND aircrafts.location = airports.location
AND fuel_station = 'yes';

Download MySQL sample database dump here.

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