I have a question related to correct handling of returns of the DAO library I'm writing for one project. This library probably is going to be used by another people, and I want to do it correctly. How I should deal with return statements of the functions of my DAO?
Example 1 I have function to getCustomer which should return String. In case a query doesn't return any result should I return null, an empty string or throw some kind of exception?
Example 2
I have a function, getCutomerList, which returns a value of type ArrayList<String>. In case a query doesn't return any result should I return null, an empty ArrayList or throw some exception?
Example 3
Some SQL exception was detected, what should I do, throw exception or do try..catch of the block where it can occur?
What is the "good" practice or "best" practice to apply in my case?