Question

我有一个表格，其中包含单位的详细信息 - 此表格的内容类似于以下内容：

| flat    | description  | Amount   | Date    
--------------------------------------
| flat1 | electricity    | 1         |1/1/2016
| flat1 | water          | 2         |1/1/2016
| flat1 | levy           | 3         |1/1/2016
| flat2 | electricity    | 1         |1/1/2016
| flat2 | water          | 2         |1/1/2016
| flat2 | levy           | 3         |1/1/2016

我需要一个可以产生如下内容的SQL视图，我们将不胜感激任何帮助：

| Flat  | electricity | water|levy | next description| and so on  | 
---------------------------------------------------------------
| flat1 | 1           | 2    | 3   | next amount     | next amount |
| flat2 | 1           | 2    | 3   | next amount     | next amount |

Answer 1

这称为表pivoting。这是使用conditional aggregation的一个选项，假设您知道潜在列的数量：

select flat, 
    max(case when description = 'electricity' then amount end) electricity,
    max(case when description = 'water' then amount end) water,
    max(case when description = 'levy' then amount end) levy
from yourtable
group by flat

如果您不知道最大列数，请查看dynamic pivot - 有很多关于如何操作的示例：

https://stackoverflow.com/a/10404455/1073631

Answer 2

drop table #temp
create table #temp (flat varchar(5), description varchar(128), amount int, date datetime)
insert into #temp (flat, description, amount, date) values
('flat1','electricity',1,'1/1/2016'),
('flat1','water',2,'1/1/2016'),
('flat1','levy',3,'1/1/2016'),
('flat2','electricity',1,'1/1/2016'),
('flat2','water',2,'1/1/2016'),
('flat2','levy',3,'1/1/2016')

select * from #temp


DECLARE @cols AS NVARCHAR(MAX),
        @query  AS NVARCHAR(MAX);

SET @cols = STUFF((SELECT distinct ',' + QUOTENAME(description) 
            FROM #temp
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT flat, ' + @cols + ' from 
            (select flat,amount, description from #temp) x
            pivot 
            (
                max(amount)
                for description in (' + @cols + ')
            ) p '


execute(@query)

您可以通过在@query部分中放置WHERE子句来添加日期过滤器。即来自#temp，其中日期介于＆lt; 1/1 / 2016＆＃39;和＆＃39; 3/1 2016＆＃39;

将多行转换为具有同一行标题的列

2 个答案: