请教关于查询问题

Question

select sum(decode(sign(substr(to_char(code),1,3)-135),-1,1,0)) 小于135,
sum(decode(sign(substr(to_char(code),1,3)-135),-1,0,1)) 大于等于135 
from yourtable

Answer 1

或者：
select 
(select count(*) from yourtable where substr(code,1,3)<135) 小于135,
(select count(*) from yourtable where substr(code,1,3)>=135) 大于等于135 
from dual;

Answer 2

select count(*) from yourtable 
where to_number(substr(code,1,3))<135
or to_number(substr(code,1,3))>=135

Answer 3

select 
(select count(*) from yourtable where substr(code,1,3)<135) 小于135,
(select count(*) from yourtable where substr(code,1,3)>=135) 大于等于135 
from dual;

Answer 4

select sum(decode(sign(substr(code,1,3)-135),-1,1)) 少于135,sum(decode(sign(substr(code,1,3)-135),1,1)) 大于135 from tabname;