U specificeert uw RDBMS niet, dus hier is het in MySQL
DELETE teammembers FROM teammembers
JOIN teams on teammembers.teamId = teams.teamId
WHERE teams.eventId = 1
U specificeert uw RDBMS niet, dus hier is het in MySQL
DELETE teammembers FROM teammembers
JOIN teams on teammembers.teamId = teams.teamId
WHERE teams.eventId = 1