Nếu bạn chỉ có một số vị trí, bạn có thể làm điều đó với PIVOT
từ khóa
select
UserID,
UserName,
[1] as Position1,
[2] as Position2,
[3] as Position3
from
(
select
U.UserID, U.UserName, P.PositionName,
row_number() over (partition by U.UserID order by P.PositionName) as RowNum
from Positions_Users as PU
inner join Positions as P on P.PositionID = PU.PositionID
inner join Users as U on U.UserID = PU.UserID
) as P
pivot
(
min(P.PositionName)
for P.RowNum in ([1], [2], [3])
) as PIV
Tuy nhiên, nếu bạn muốn có một số cột động, bạn phải sử dụng SQL động, như thế này
declare @stmt nvarchar(max), @stmt_columns1 nvarchar(max), @stmt_columns2 nvarchar(max)
declare @Temp_Data table (RowNum nvarchar(max))
insert into @Temp_Data
select distinct row_number() over (partition by U.UserID order by P.PositionName) as RowNum
from Positions_Users as PU
inner join Positions as P on P.PositionID = PU.PositionID
inner join Users as U on U.UserID = PU.UserID
select @stmt_columns1 = stuff((select ', [' + RowNum + ']' from @Temp_Data for xml path(''), type).value('.', 'nvarchar(max)'), 1, 2, '')
select @stmt_columns2 = stuff((select ', [' + RowNum + '] as Position' + RowNum from @Temp_Data for xml path(''), type).value('.', 'nvarchar(max)'), 1, 2, '')
select @stmt = '
select
UserID,
UserName,' + @stmt_columns2 + '
from
(
select
U.UserID, U.UserName, P.PositionName,
row_number() over (partition by U.UserID order by P.PositionName) as RowNum
from Positions_Users as PU
inner join Positions as P on P.PositionID = PU.PositionID
inner join Users as U on U.UserID = PU.UserID
) as P
pivot
(
min(P.PositionName)
for P.RowNum in (' + @stmt_columns1 + ')
) as PIV'
exec sp_executesql @stmt = @stmt