MySQL 如何修改SQL语句，去掉语句中的or

问题遇到的现象和发生背景

MySQL 如何修改SQL语句，去掉语句中的or，因为有or导致索引失效

问题相关代码，请勿粘贴截图

select bid from book a ,querybook b where ( a.bname in (b.bname) or b.bname = "" ) and
(a.bauthor in (b.bauthor) or b.bauthor = "" ) and
(a.barea in (b.barea) or b.barea = "" )
SQL作用是当查询条件为空时默认查询全部数据，不为空是则按照条件进行查询