source: database/Advanced Reports for database/Top 10 employees who have answered the most amount of request in the last month.txt@ 06ebe74

CREATE OR REPLACE FUNCTION get_top_10_employees_by_requests_last_month()
RETURNS TABLE (
    id BIGINT,
    employee_name TEXT,
    number_of_requests BIGINT
)
LANGUAGE plpgsql
AS $$
BEGIN
    RETURN QUERY
    SELECT
        e.id,
        p.name AS employee_name,
        COUNT(DISTINCT a.request_num) AS number_of_requests
    FROM employees e
    JOIN personal p
        ON e.id = p.id
    JOIN answers a
        ON e.id = a.id
    JOIN request r
        ON a.request_num = r.request_num
    WHERE r.date_and_time >= date_trunc('month', CURRENT_DATE) - INTERVAL '1 month'
      AND r.date_and_time < date_trunc('month', CURRENT_DATE)
    GROUP BY
        e.id,
        p.name
    ORDER BY
        number_of_requests DESC
    LIMIT 10;
END;
$$;