Could you explain the meaning of each command-line based on this ERD?

public, patient [table] patientid int4 not null I patientname varchar(25) patientid_fk public.physician [table] physicianid int4 not nulli physicianname varchar(50) public patienttreatment_t [table] O patientid int4 not null physicianid_fk Ophysicianid int4 not null treatmentcode_fk ostreatmentcode varchar(12) not null patienttreatmentdate date not null patienttreatmenttime time not null patienttreatmentresults varchar(50) not null public treatment [table] treatmentcode varchar(12) not nullit treatmentdescription varchar(50) CREATE TABLE PatientTreatment_T ( PatientID int NOT NULL, PhysicianID int NOT NULL, TreatmentCode VARCHAR(12) NOT NULL, PatientTreatmentDate date NOT NULL, PatientTreatmentTime time NOT NULL, PatientTreatmentResults VARCHAR(50) NOT NULL, CONSTRAINT PatientID_FK Foreign KEY (PatientID) REFERENCES Patient(PatientID), CONSTRAINT PhysicianID_FK Foreign KEY (PhysicianID) REFERENCES Physician (PhysicianID), CONSTRAINT TreatmentCode_FK Foreign KEY (TreatmentCode) REFERENCES Treatment (TreatmentCode), CONSTRAINT PatientTreatment_T_PK Primary Key (PatientID, PhysicianID, TreatmentCode, PatientTreatmentDate, PatientTreatmentTime)); INSERT INTO PatientTreatment_T VALUES ('112', '58', 'TR45', '05/23/2010', '10:30 am', 'Patient is recovering.'), ('112', '58', 'TR44', '05/23/2010', '10:30 am', 'Patient has recovered.'), ('224', '58', 'TR44', '05/23/2010', 10:30 am', 'Patient recovery is good.')