Several columns' values into a single column in Cdatagridview?

Hello i’m new to yii. I want to customize the table in datagridview.

I have two tables :

Category :

id_cat

a_code

a_name

b_code

b_name

c_code

c_name

Usage

id

id_cat

detail

volume

price

Instead of having a table like this :

7006

cap1.PNG

I want something like this :

7005

cap2.PNG

does anyone have idea how to do this? thank you