<SQL>求A、B两张表占两表数据量总和的比例

Question

有两张表

A data_index_err
B data_index_his
求两张表占A、B数据总数的比例

with table_sum as 
(select count(1) as total from data_index_his
union all 
select count(1) as total from data_index_err) 
select sum(total) as total  from table_sum 
union all 
select total/sum(total)*1.0 as "percent" 
from table_sum group by total;

结果：

为什么结果和期望的不一致啊？~~~~