SQL，group by分组后分别计算组内不同值的数量

select name as 姓名,
sum( case when cargo='笔' then 1 else 0 end ) as 笔,
sum( case when cargo='橡皮' then 1 else 0 end ) as 橡皮
from shopping group by name;

转载于:https://www.cnblogs.com/fangyan1994/p/10537354.html