$newquery = User::find()
->select(['username',new Expression('count(id) as id')])
-> leftJoin('event', 'event.id_operator=user.id OR event.id_driver=user.id OR event.id_operator2=user.id OR event.id_journalist=user.id')
->where(['event.status'=>1])
->groupBy(['username'])
->all();
SELECT
operators.username,
journalist.username,
driver.username
FROM event
INNER JOIN user operators
ON event.id_operator = operators.id
INNER JOIN user journalist
ON event.id_journalist = journalist.id
INNER JOIN user driver
ON event.id_driver = driver.id