更新行，而不是创建新的条目数据库android。

I have been working on recipe from Android recipe book to utilize a database for storing events. Current code allows me to add new entries but I am unable to modify any of the added entries. What I need is a database with predefined number of rows(48) with functionality of updating these rows through corresponding edittext fields. Can anyone help me to modify the following code to achieve this please? I am new to android coding and I need to start with this database. I have been working on recipe from Android reci