Which businesses with the category name Accessories have opening hours before 7AM?
opening hours before 7AM refer to opening_time < '7AM'; businesses refer to business_id;
SELECT T1.business_id FROM Business_Hours AS T1 INNER JOIN Business_Categories AS T2 ON T1.business_id = T2.business_id INNER JOIN Categories AS T3 ON T2.category_id = T3.category_id WHERE T3.category_name = 'Accessories' AND SUBSTR(T1.opening_time, -4, 2) * 1 < 7 AND T1.opening_time LIKE '%AM'