如何使用一个表中的值作为 SQL 服务器中新表中的列名？

Question

I have a table that looks like this:

EmployeeName	City
Maria	Chicago
John	Chicago
Anna	LA
Peter	LA
Carrie	NYC

And I need to create a table that will look like this:

Chicago	LA	NYC
Maria	Anna	Carrie
John	Peter

I found this

SELECT (ColumnNames)  
FROM (TableName)  
PIVOT
(  
 AggregateFunction(ColumnToBeAggregated)
  FOR PivotColumn IN (PivotColumnValues)
) AS (Alias);   

But I am confused which aggregate function to use since the values are not numeric and also my table has too many Cities to write them manually.

Answer 1

You can PIVOT with the addition of a new column. In this simple case I used the window function dense_rank() over()

Results

Declare @YourTable Table ([EmployeeName] varchar(50),[City] varchar(50))  Insert Into @YourTable Values 
 ('Maria','Chicago')
,('John','Chicago')
,('Anna','LA')
,('Peter','LA')
,('Carrie','NYC')
 

Select  *
 From  (
        Select EmployeeName
              ,City
              ,RN = dense_rank() over (partition by city order by EmployeeName desc) 
         From @YourTable
       ) src
 Pivot ( max(EmployeeName) for City in ( [Chicago],[LA],[NYC]) )pvt

Results

RN  Chicago LA      NYC
1   Maria   Peter   Carrie
2   John    Anna    NULL

UPDATE- Dynamic Approach

Declare @SQL varchar(max) = '
Select  *
 From  (
        Select EmployeeName
              ,City
              ,RN = dense_rank() over (partition by city order by EmployeeName desc) 
         From YourTable
       ) src
 Pivot ( max(EmployeeName) for City in ( '+ (Select string_agg(quotename(City),',') From  (Select distinct City from YourTable) A) +' ) )pvt
'
Exec(@SQL)