SELECT count(*),
sum(case when identify_type=01 then 1 else 0 end ),
sum(case when identify_type=02 then 1 else 0 end ),
sum(case when identify_type=03 then 1 else 0 end ) FROM `user_info`;
mysql 一个表内根据字段对应值不同查询统计总数
原文：http://www.cnblogs.com/jiafeimao-dabai/p/7737259.html
