问题
I am new to blackberry development. I want to do data manipulation (CRUD) for a small project. Can you help me understand different options that can be used for blackberry data persistence for O.S 4.5? I want to know and explore all possible data persistence models for blackberry O.S 4.5.
I did some searching and found blackberry data persistence in Persistence store. The problem that I am facing is how to update an existing record. Should I load all the objects and find the required object, delete it and then insert a new record or is there any other quick way to search?
回答1:
I tried this at work.
This is a library to help with persistent object.
It has a lot of integrated functions like binary tree, sorting, etc...
It's pretty fast based on the test I've done, and if you are going to sell your software, the licenses price are low.
Your other option is Sybase UltraLiteJ, but I's pretty dam slow, but it supports SQL language.
Or you code yourself a nice implementation based on the BlackBerry Persistence Object that you could use in your other apps.
回答2:
We need to read and commit whole persistent object, ex. using Vector or LongHashtableCollection if we need to read one element we will have to read all of them, if you need to add/delete/modify we need to read and commit whole collection.
See also SO - Blackberry - application settings save/load
来源：https://stackoverflow.com/questions/2175766/blackberry-data-persistence-o-s-4-5