CREATE TABLE Dogs (date_arrived VARCHAR(255), date_departed VARCHAR(255), dog_id VARCHAR(255)); CREATE TABLE Treatments (dog_id VARCHAR(255))
What are the arriving date and the departing date of the dogs who have gone through a treatment?
    
SQL: SELECT DISTINCT T1.date_arrived, T1.date_departed FROM Dogs AS T1 JOIN Treatments AS T2 ON T1.dog_id = T2.dog_id