这个行转列的SQL该如何改
这个行转列的SQL该怎么改?
表结构


我原本的SQL
测试的时候数据随便弄的,但实际用的时候提示RecordValue不能将值nvarchar转为int
这SQL是我网上搜的,自个改了下 求帮忙
------解决方案--------------------
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------解决方案--------------------
select RecordTime ,
[测点0]=max(CASE WHEN [Spotid]=0 THEN convert(int,RecordValue) else 0 end ) ,
[测点1]=max(CASE WHEN [Spotid]=1 THEN convert(int,RecordValue) else 0 end ) ,
[测点2]=max(CASE WHEN [Spotid]=2 THEN convert(int,RecordValue) else 0 end )
from History_Record group by RecordTime
------解决方案--------------------
建个索引试试呢..
------解决方案--------------------
给个例子你参考下
表结构
我原本的SQL
select RecordTime ,
[测点0]=max(CASE WHEN [Spotid]=0 THEN RecordValue else 0 end ) ,
[测点1]=max(CASE WHEN [Spotid]=1 THEN RecordValue else 0 end ) ,
[测点2]=max(CASE WHEN [Spotid]=2 THEN RecordValue else 0 end )
from History_Record group by RecordTime
测试的时候数据随便弄的,但实际用的时候提示RecordValue不能将值nvarchar转为int
这SQL是我网上搜的,自个改了下 求帮忙
SQL
行转列
------解决方案--------------------
convert(int , RecordValue)
------解决方案--------------------
select RecordTime ,
[测点0]=max(CASE WHEN [Spotid]=0 THEN cast(RecordValue as int) else 0 end ) ,
[测点1]=max(CASE WHEN [Spotid]=1 THEN cast(RecordValue as int) else 0 end ) ,
[测点2]=max(CASE WHEN [Spotid]=2 THEN cast(RecordValue as int) else 0 end )
from History_Record
group by RecordTime
------解决方案--------------------
select RecordTime ,
[测点0]=max(CASE WHEN [Spotid]=0 THEN convert(int,RecordValue) else 0 end ) ,
[测点1]=max(CASE WHEN [Spotid]=1 THEN convert(int,RecordValue) else 0 end ) ,
[测点2]=max(CASE WHEN [Spotid]=2 THEN convert(int,RecordValue) else 0 end )
from History_Record group by RecordTime
------解决方案--------------------
建个索引试试呢..
create index ix_History_Record on History_Record(RecordTime,Spotid,RecordValue)
------解决方案--------------------
给个例子你参考下
12345678910111213141516171819202122 if exists(select 1 from sys.tables where name='test20130507') drop table test20130507 go create table test20130507(a varchar(20),b varchar(20),c varchar(20)) insert into test20130507 select '20130508','8:00~9:00','张三' union allselect '20130508','9:00~10:00','测试' union allselect '20130509','8:00~9:00','李四' union allselect '20130509','8:00~9:00','再测' union allselect '20130509','9:00~10:00','再测1' union allselect '20130609','9:00~10:00','再测1'go declare @sql varchar(max)=''select @sql=@sql+',max(case when a='''+a+''' then c else null end)as '''+a+'''' from (select distinct a from test20130507)a exec ('select b'+@sql+' from (select distinct a,b, c=stuff((select '',''+c from test20130507 where a.a=a and a.b=b for xml path('''')),1,1,'''') from test20130507 a)a group by b')