参考:
SQLite数据库版本升级
https://blog.csdn.net/feibendexiaoma/article/details/79526187
Android数据库Sqlite的基本用法及升级策略
https://blog.csdn.net/u013700502/article/details/78764917?utm_medium=distribute.pc_relevant.none-task-blog-2~default~baidujs_baidulandingword~default-1.pc_relevant_paycolumn_v2&spm=1001.2101.3001.4242.2&utm_relevant_index=4
update和upgrade的主要区别
https://blog.csdn.net/liuzehn/article/details/83651587
