sql从一堆数字中查询出正数的总个数和负数总个数

数据库

sql

SELECT
	sum(CASE WHEN mark < 0 THEN 1 ELSE 0 END) AS markReduce,
	sum(CASE WHEN mark >= 0 THEN 1 ELSE 0 END) AS markAdd
FROM
	evaluation_log

结果

case when使用学习https://www.cnblogs.com/martinzhang/p/3220595.html