Event invitation
| Column | Type | References | Comments |
| id | Integer | Primary key | |
| guid | String | ||
| vdb_id | Integer | ||
| owner_id | Integer | db_person.id | Owner ID |
| calendar_event_id | Integer | db_calendar_event.id | Calendar event ID |
| status | Integer | 0 = unknown, 1 = invitee accepted, 2 = invitee declined | |
| invitation_type | Integer | 0 = required, 1 = Optional, 2 = Copy | |
| invitee_id | Integer | db_person.id | Invitee user id in case the invitee is a user of the system |
| invitee_email | String | Invitee Email | |
| comments | String | Invitee entered comments (e.g. reason for refusal) |