How to populate Expandable list view child data using sqlite in android?

Sell Activity

** I am creating a BookStore Automation app and in sell activity as shown in the picture I am using expandable list view . The group header is name of category of book which I have populated using array list . And I want to populate child of each group with data fetched from sqlite database (i.e name of any book under that category ) . I am new to android development ,plz tell me how should I proceed ? **