| # Task: 018 | |
| **Database:** retails | |
| ## Question | |
| Count the number of customers that have used air shipping. | |
| ## Gold Query | |
| ```sql | |
| SELECT COUNT(DISTINCT c.c_custkey) | |
| FROM customer c | |
| JOIN orders o ON c.c_custkey = o.o_custkey | |
| JOIN lineitem l ON o.o_orderkey = l.l_orderkey | |
| WHERE l.l_shipmode IN ('AIR', 'REG AIR'); | |
| ``` | |
| **Execution Result:** | |
| | COUNT(DISTINCT c.c_custkey) | | |
| |-------------------------------| | |
| | 92006 | | |
| *1 rows* |