都市逍遥传之金色年华:SQL语句 count(*)求差 语句怎么写?

来源:百度文库 编辑:高校问答 时间:2024/04/28 12:51:54
现有一个表T,T的一个字段F,F的值有四种 "0","1","2","3" ,现求 "0"和"1"的总纪录条数和"2"和"3"的总纪录条数的差,SQL语句怎么写,用一条语句

select sum(case when f in ('0', '1') then 1
case when f in ('2', '3') then -1 else 0 end)
from t

SELECT ((SELECT COUNT(*) FROM T WHERE F IN ('0','1'))-(SELECT COUNT(*) FROM T WHERE F IN ('2','3')))