ค้นหาบาร์ทั้งหมดในดัลลัสไม่จำเป็นต้องใช้ตารางทั้งหมด
Find all Bars in DallasIt is not neccessary to use all the tables.
 category:  id [ int]  business_id [ varchar]  category_name [ varchar] 
SELECT business.name FROM business, category WHERE business.city = 'Dallas' AND category.business_id = business.business_id AND category.category_name = 'Bars'