Come scrivere colonne di query dinamiche in righe in SQL Server?

Potresti provare a usare UNPIVOT, in questo modo...

SELECT empid, empvalues
FROM (
    select empid, addr, convert(varchar(100), sal) as sal,  convert(varchar(100), doj, 103) as doj
    from emp
) pv
UNPIVOT
(
    empvalues
    FOR ev in (addr, sal, doj)
) AS ev

produce questo output...

Risorse di riferimento...

https://codingsight.com/understanding-pivot-unpivot- e-dichiarazioni-reverse-pivot/ https://docs.microsoft.com/en-us/sql/t-sql/queries/from-using-pivot-and-unpivot?view=sql-server-ver15