如果你正在使用SQL Server，那么有几种方法可以将数据行转置为列。
聚合函数 / CASE: 你可以使用一个带有CASE表达式的聚合函数和row_number()。这个版本需要你知道要变成列的值的数量：
select id,
name,
max(case when rn = 1 then employer end) employer1,
max(case when rn = 1 then IncomeType end) IncomeType1,
max(case when rn = 1 then Amount end) Amount1,
max(case when rn = 2 then employer end) employer2,
max(case when rn = 2 then IncomeType end) IncomeType2,
max(case when rn = 2 then Amount end) Amount2,
max(case when rn = 3 then employer end) employer3,
max(case when rn = 3 then IncomeType end) IncomeType3,
max(case when rn = 3 then Amount end) Amount3
from
(
select id, name, employer, incometype, amount,
row_number() over(partition by id order by employer) rn
from yourtable
) src
group by id, name;
请查看带演示的
SQL Fiddle。
PIVOT/UNPIVOT: 您可以使用UNPIVOT和PIVOT函数来获得结果。 UNPIVOT将您的多列
Employer，
IncomeType和
Amount转换为多行，然后应用PIVOT。 假设您知道值的数量并且使用SQL Server 2005+，则可以使用带有UNION ALL的CROSS APPLY来进行UNPIVOT。
select id, name,
employer1, incometype1, amount1,
employer2, incometype2, amount2,
employer3, incometype3, amount3
from
(
select id, name, col+cast(rn as varchar(10)) col, value
from
(
select id, name, employer, incometype, amount,
row_number() over(partition by id order by employer) rn
from yourtable
) t
cross apply
(
select 'employer', employer union all
select 'incometype', incometype union all
select 'amount', cast(amount as varchar(50))
) c (col, value)
) src
pivot
(
max(value)
for col in (employer1, incometype1, amount1,
employer2, incometype2, amount2,
employer3, incometype3, amount3)
) piv;
请查看带演示的SQL Fiddle。
动态版本：最后，如果你有未知数量的值，则需要使用动态SQL生成结果。
DECLARE @cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX)
select @cols = STUFF((SELECT ',' + QUOTENAME(col+cast(rn as varchar(10)))
from
(
select row_number() over(partition by id order by employer) rn
from yourtable
) d
cross apply
(
select 'employer', 1 union all
select 'incometype', 2 union all
select 'amount', 3
) c (col, so)
group by col, rn, so
order by rn, so
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = 'SELECT id, name,' + @cols + '
from
(
select id, name, col+cast(rn as varchar(10)) col, value
from
(
select id, name, employer, incometype, amount,
row_number() over(partition by id order by employer) rn
from yourtable
) t
cross apply
(
select ''employer'', employer union all
select ''incometype'', incometype union all
select ''amount'', cast(amount as varchar(50))
) c (col, value)
) x
pivot
(
max(value)
for col in (' + @cols + ')
) p '
execute(@query);
请查看带演示的SQL Fiddle。所有版本都会给出结果：
| ID | NAME | EMPLOYER1 | INCOMETYPE1 | AMOUNT1 | EMPLOYER2 | INCOMETYPE2 | AMOUNT2 | EMPLOYER3 | INCOMETYPE3 | AMOUNT3 |
| 123 | XYZ | ABC.Inc | EarningsformJob | 200 | ChildSupport | Support | 500 | Self | Self Employment | 300 |
