id       category_title      category_parent
----     --------------      ---------------
 1          sport                   0
 2        electronic                0
 3         football                 1
 4        volleyball                1
 5         laptop                   2
 6        television                2
 7        basketball                1

id       product_name       product_category(referenced to id column from category table)
----     --------------      ---------------
 1         product1                 3
 2         product2                 3
 3         product3                 4
 4         product4                 4
 5         product5                 5
 6         product6                 6
 7         product7                 7