fix case insensitive in mysql but case senstiive in program

[choucmei]

In mysql use utf8_general_ci will case，eaxmple : 'a' = ‘A' , use utf8_bin will sort by asscii ,example: 'A' < 'a'. But will sort by asscii in java.

Use binary function like select * from table order by binary id is not good, because it result to filesort is not index