case when语句的应用
case when语句运用
1 select b.cur_branch, 2 count(p.conttract_id), 3 sum(case when p.aff_date is null then p.payable_money else 0 end), 4 sum(case when p.aff_date is null and p.fee_item ='租金' then p.payable_money else 0 end), 5 sum(case when p.aff_date is null and p.fee_item ='电费' then p.payable_money else 0 end), 6 sum(case when p.aff_date is not null then 1 else 0 end), 7 sum(case when p.aff_date is null then 1 else 0 end) 8 from WG_PJHSB p, wg_jzmb b 9 where p.station_id = b.station_code 10 group by b.cur_branch 11 order by b.cur_branch
运用1：sum（case when p.aff_date is null then p.payable_money else 0 end）
累加票据金额
运用2：sum(case when 条件语句l then 1 else 0 end)
累加计数使用。
