Oracle LISTAGG: Combine Columns into One Row

You can use the LISTAGG function in Oracle to concatenate multiple columns into one row. This function combines the values of multiple columns into a single string, and allows you to specify a delimiter.

For example, suppose you have a table named “employee” with three columns: id, name, and department. You can use the following statement to concatenate the values of these three columns into one row:

SELECT id, LISTAGG(name || ', ' || department, ', ') WITHIN GROUP (ORDER BY id) AS combined_info
FROM employee
GROUP BY id;

In this example, we are using the LISTAGG function to concatenate the values of the name and department columns together, separated by a comma, and sorted according to the id column. Finally, we use the GROUP BY clause to group the results by id.