ListAgg Example

Example:

How to display department_id and corresponding employees name delimited with ',' operator?

For Example:

Data looks as follows:

We need to convert above data as follow:

Query:

SELECT DEPARTMENT_ID , 

LISTAGG(FIRST_NAME||'.'||LAST_NAME,', ') WITHIN GROUP (ORDER BY FIRST_NAME) EMPLOYEE_LIST FROM HR.EMPLOYEES

GROUP BY DEPARTMENT_ID;