select * from testtable; type subtype value a sa 1b sb 1a sb errorb sa errora sb 1b sb 1c sa errorc sb 1c sc 1c sc 1c sa error select sum(`value`) from testtable where value != 'error' AND type ='b'; sum(`value`) 2 SELECT type,subtype,SUM(value) AS T…
sql之分段统计 需求:获取一个县所有家庭人数在1-2人,3-4人,5-6人,6人以上的家庭数的数组 思路:通过CASE WHEN 将 CBFCYSL分组,然后统计数据条数. 语句: SELECT THEN '1-2' THEN '2-3' THEN '4-5' THEN '6+' ELSE '其他' END AS QJ, COUNT(CBFCYSL) AS NUM FROM TDCBJYQ.dbo.CBF GROUP BY THEN '1-2' THEN '2-3' THEN '4-5' TH…
mvc linq to sql,linq to entity,sum,null 昨天写了段sum的统计语句, decimal sums sums = ( from fac in db.Apply where fa.state == 1 select fac.num ).Sum(), 然后一运行,报错 Message=The cast to value type 'System.Decimal' failed because the materialized value is null. Eit…