SQL DELETE with JOIN and SELECT "1" - Tutorial

DELETE hospital, doctor, posts, registration\nFROM hospital\nLEFT JOIN doctor ON hospital.id = doctor.host_id\nLEFT JOIN posts ON doctor.id = posts.doctor_id\nLEFT JOIN registration ON doctor.id = registration.doctor_id\nWHERE hospital.id = 11;\n\nSELECT "1";