sqldeclarevarchar

❶ sql語句統計數量，統計一個欄位的值的數量

select type,count(*) as 總數量,
sum(case when level='一級' then 1 else 0 end) as 一級,
sum(case when level='二級' then 1 else 0 end) as 二級,
sum(case when level='三級' then 1 else 0 end) as 三級
from table group by type

樓上的應該改改吧