原题
思路
不是个好题，case when。
代码
select id, sum(case `month` when 'Jan' then revenue else null end) as Jan_Revenue, sum(case `month` when 'Feb' then revenue else null end) as Feb_Revenue, sum(case `month` when 'Mar' then revenue else null end) as Mar_Revenue, sum(case `month` when 'Apr' then revenue else null end) as Apr_Revenue, sum(case `month` when 'May' then revenue else null end) as May_Revenue, sum(case `month` when 'Jun' then revenue else null end) as Jun_Revenue, sum(case `month` when 'Jul' then revenue else null end) as Jul_Revenue, sum(case `month` when 'Aug' then revenue else null end) as Aug_Revenue, sum(case `month` when 'Sep' then revenue else null end) as Sep_Revenue, sum(case `month` when 'Oct' then revenue else null end) as Oct_Revenue, sum(case `month` when 'Nov' then revenue else null end) as Nov_Revenue, sum(case `month` when 'Dec' then revenue else null end) as Dec_Revenue
from Department group by id