解决方法

1.可以将查询条件用binary()括起来

select * from TableA where binary columnA ='aaa';

2.可以修改该字段的collation 为 binary

ALTER TABLE TABLENAME MODIFY COLUMN COLUMNNAME VARCHAR(50) BINARY CHARACTER SET utf8 COLLATE utf8_bin DEFAULT NULL;

3.在建表时时候加以标识

create table some_table(
   str char(20) binary 
)