9. The following information is required in the ward computer management system of a hospital: Department: Department name, department address, department telephone Ward: ward number, bed number, department name Doctor: name, title, department name, age, work permit number Patient: medical record number, name, gender, diagnosis, attending doctor, ward number Among them, a department has multiple wards and multiple doctors; A ward can only belong to one department; A doctor only belongs to department, but can be responsible for the diagnosis and treatment of multiple patients. There is only one doctor in charge of a patient. (1) Draw the ER diagram according to the above semantics, and indicate the attribute of the entity, the type of connection and the identifier of the entity in the ER diagram. (2) The ER model is transformed into a relational model, and the primary key and foreign key of each relational schema are pointed out. one