Question

I have a simple relation in which category and subcategories are differentiated by parent_id and category has a parent_id 0 and subcategory has category_id as its parent_id.What i want to do is to select first subcategory of a first category.

for this i am using

SELECT cat_id FROM member_product_cat WHERE cat_parent_id !=0 HAVING
cat_parent_id=min(cat_parent_id) LIMIT 1

but it gives me an error.I know i can do the same by

SELECT cat_id FROM member_product_cat WHERE cat_parent_id=(Select
min(cat_parent_id) from member_product_cat where cat_parent_id !=0)
LIMIT 1

But what is wrong in my first approach?isnt it for this we have having clause?.

Regards
Himanshu Sharma

Answer 1

The HAVING clause was added to SQL because the WHERE keyword could not be used with aggregate functions. So you do not need HAVING there at all.