查詢結果字段介紹：c_ex49是業務員id，tmonth是年-月，tamt是對應月的金額，想要最後查詢的效果是：把每個業務員的每個月的金額顯示成一行，我這裏只到了1-10月份，不過顯示還是要顯示1-12月的，沒有的就顯示0
上圖使用多行轉多列，效果爲：
下面是具體步驟：
然後，執行上面的邏輯後，就由最初的多行變成了多列
最初的：
select c_ex49,CONVERT(VarChar(7),c_starttime, 120) as tmonth,SUM(CAST(c_ex9 as float)) as tamt from CRM_CONTRACT
where CONVERT(VarChar(7),c_starttime, 120)>='2019-01' and CONVERT(VarChar(7),c_starttime, 120)<='2019-12' and c_ex49='scrmsass_yangli'
group by c_ex49,CONVERT(VarChar(7),c_starttime, 120)
執行後的：
select c_ex49,
sum(oneMonth) as oneMonth,sum(twoMonth) as twoMonth,sum(threeMonth) as threeMonth,sum(fourMonth) as fourMonth,sum(fiveMonth) as fiveMonth,sum(sixMonth) as sixMonth,
sum(sevenMonth) as sevenMonth,sum(eightMonth) as eightMonth,sum(nineMonth) as nineMonth,sum(tenMonth) as tenMonth,sum(elevenMonth) as elevenMonth,sum(telvMonth) as telvMonth from (
select c_ex49,
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-01' then c_ex9 else '0.0' end as float)) 'oneMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-02' then c_ex9 else '0.0' end as float)) 'twoMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-03' then c_ex9 else '0.0' end as float)) 'threeMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-04' then c_ex9 else '0.0' end as float)) 'fourMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-05' then c_ex9 else '0.0' end as float)) 'fiveMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-06' then c_ex9 else '0.0' end as float)) 'sixMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-07' then c_ex9 else '0.0' end as float)) 'sevenMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-08' then c_ex9 else '0.0' end as float)) 'eightMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-09' then c_ex9 else '0.0' end as float)) 'nineMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-10' then c_ex9 else '0.0' end as float)) 'tenMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-11' then c_ex9 else '0.0' end as float)) 'elevenMonth',
sum(CAST(case when CONVERT(VarChar(7),c_starttime, 120)='2019-12' then c_ex9 else '0.0' end as float)) 'telvMonth'
from CRM_CONTRACT where CONVERT(VarChar(7),c_starttime, 120)>='2019-01' and CONVERT(VarChar(7),c_starttime, 120)<='2019-12' and c_ex49='scrmsass_yangli'
group by c_ex49,CONVERT(VarChar(7),c_starttime, 120)
) t1 group by c_ex49
