SQL- 行转列，多行转多列 - max 函数

效果如图，把同一个 code， 按 cate 列分为 Actual 和 Budget 两行，再把mode 每种类型转换成 列名 ，主要用到了 max 函数，很实用

 if exists(select * from tempdb..sysobjects where id=object_id('tempdb..#t'))
 drop table #t
   create table #t(
     code varchar(10),
 　　cname nvarchar(30),
     fyear varchar(30),
     cate varchar(10),
     mt numeric(18,4),
     amt numeric(18,2),
     mode nvarchar(20),
     mo_mt numeric(18,4),
     mo_avgfee numeric(18,2),
     mo_rate nvarchar(20)
　　)
insert into #t
select            '',N'深圳','','Actual','','','BLK',10,1,'3.57%'
 union all select '',N'深圳','','Actual','','','V15',20,2,'7.14%'
 union all select '',N'深圳','','Actual','','','V5',30,3,'10.71%'
 union all select '',N'深圳','','Actual','','','V0',40,4,'14.29%'
 union all select '',N'深圳','','Actual','','','V20',50,5,'17.86%'
 union all select '',N'深圳','','Actual','','','V10',60,6,'21.43%'
 union all select '',N'深圳','','Actual','','','V25',70,7,'25.00%'
 union all select '',N'深圳','','Budget','','','BLK',10,1,'3.57'
 union all select '',N'深圳','','Budget','','','V15',20,2,'7.14%'
 union all select '',N'深圳','','Budget','','','V5',30,3,'10.71%'
 union all select '',N'深圳','','Budget','','','V0',40,4,'14.29%'
 union all select '',N'深圳','','Budget','','','V20',50,5,'17.86%'
 union all select '',N'深圳','','Budget','','','V10',60,6,'21.43%'
 union all select '',N'深圳','','Budget','','','V25',70,7,'25.00%'
 select * from #t

 --增加一个强制mode 排序，比如从 vo v1 v2 依次排序
 if exists(select * from tempdb..sysobjects where id=object_id('tempdb..#sort'))
 drop table #sort
 　　create Table #sort
　　(
 　　mode varchar(10),
　　)
  insert into #sort
  select distinct mode FROM #t   GROUP BY mode order by mode
  -- select * from #sort

   declare @sql nvarchar(max)     --声明一个变量
 SET @sql = '
SELECT code '
+',cname '
+',fyear '
+',cate ' --+ N'''类别'''
+',isnull(mt,0) mt' -- + N'''吨数'''
+',isnull(amt,0) amt'  -- + N'''金额'''
select @sql = @sql + ' , max(case mode when ''' + mode+ ''' then mo_rate  else '''' end) [' + mode+ ']'
            + ' , max(case mode when ''' + mode+ ''' then mo_avgfee  else 0 end) [' + mode+ '_unit]'
from (select  mode FROM #sort ) as a
--print @sql
set @sql = @sql + ' from #t group by code, cname,fyear,cate,mt,amt  order by code,fyear  '
print @sql
exec(@sql)   --执行该sql