What is the total number of flights that flew on August 2, 2018 with air carrier described as Horizon Air?
on August 2, 2018 refers to FL_DATE = '2018/8/2'; Horizon Air refers to Description which includs 'Horizon Air';
SELECT COUNT(*) FROM `Air Carriers` AS T1 INNER JOIN Airlines AS T2 ON T1.Code = T2.OP_CARRIER_AIRLINE_ID WHERE T1.Description LIKE '%Horizon Air%' AND T2.FL_DATE = '2018/8/2'