如何找到具有多个联接的主要类别名称？

Question

我有两个桌子

export default { 
  ...
  get event() { return event; },
}

现在我想在下面提到细节

BUSINESS_ID SUBCATEGORY_NAME MAINCATEGORY_NAME

但是我不知道该怎么办？

Answer 1

select
bus.business_id, cat2.name as subcategory_name, cat1.name as maincategory_name
from 
business_categories as bus
inner join categories as cat1 on bus.category_id = cat1.id
inner join categories as cat2 on cat1.parent_id = cat2.id