UC0008 - Volunteer for Event Session

Initiating actor: Member

A Member volunteers for a selected event session. The scenario uses Dario Petreski volunteering for the Company Stands session at MFS during Job Fair 2026.

Scenario

1. The Member opens the volunteer opportunities for Job Fair 2026.

2. The application lists event sessions and volunteer coverage.

SELECT
    es.est_name,
    es.es_start_time,
    es.location,
    es.es_title,
    est.needed_no_volunteers,
    COUNT(v.student_index) AS assigned_volunteers,
    GREATEST(est.needed_no_volunteers - COUNT(v.student_index), 0) AS missing_volunteers
FROM event_sessions es
JOIN event_session_types est
    ON est.est_name = es.est_name
LEFT JOIN volunteers v
    ON v.et_name = es.et_name
   AND v.event_title = es.event_title
   AND v.event_start_time = es.event_start_time
   AND v.est_name = es.est_name
   AND v.es_start_time = es.es_start_time
   AND v.location = es.location
WHERE es.et_name = 'Job Fair'
  AND es.event_title = 'Job Fair 2026'
  AND es.event_start_time = TIMESTAMP '2026-03-23 09:00:00'
GROUP BY
    es.est_name,
    es.es_start_time,
    es.location,
    es.es_title,
    est.needed_no_volunteers
ORDER BY es.es_start_time, es.location, es.est_name;

3. The Member chooses the Company Stands session at MFS.

4. The application checks whether the member already volunteers at the same start time.

SELECT
    v.et_name,
    v.event_title,
    v.est_name,
    v.es_start_time,
    v.location,
    v.volunteer_role
FROM volunteers v
WHERE v.student_index = 230024
  AND v.es_start_time = TIMESTAMP '2026-03-24 10:00:00';

5. The application stores the volunteer record.

INSERT INTO volunteers (
    student_index,
    et_name,
    event_title,
    event_start_time,
    est_name,
    es_start_time,
    location,
    volunteer_role
)
VALUES (
    230024,
    'Job Fair',
    'Job Fair 2026',
    TIMESTAMP '2026-03-23 09:00:00',
    'Company Stands',
    TIMESTAMP '2026-03-24 10:00:00',
    'MFS',
    'stand support'
);

6. The application refreshes the volunteer list for the selected session.

SELECT
    v.student_index,
    s.first_name,
    s.last_name,
    v.volunteer_role
FROM volunteers v
JOIN students s
    ON s.student_index = v.student_index
WHERE v.et_name = 'Job Fair'
  AND v.event_title = 'Job Fair 2026'
  AND v.event_start_time = TIMESTAMP '2026-03-23 09:00:00'
  AND v.est_name = 'Company Stands'
  AND v.es_start_time = TIMESTAMP '2026-03-24 10:00:00'
  AND v.location = 'MFS'
ORDER BY s.last_name, s.first_name;