mysql创建用户，并赋予权限：只能查某个数据库中的某张表（只读）
grant select on allindata_deb.user to lhz@% identified by 123456
grant select on test.test to test@% identified by 123456
grant select on allindata_deb.user to lhz@% identified by 123456
grant select on test.test to test@% identified by 123456