The LISTAGG function aggregates a set of string elements into one string by concatenating the strings.
Example :
Select dept,
LISTAGG(Lastname, ‘, ‘) Within Group(Order by Lastname)
As Employees
From Emptable
Group By Dept
Sample Result :
Dept Employees
Admin Adam, Ashley, Glen
IT John, Maggie, Nicolas
Sales Shaun, Trevor, Vickie