gyak3

CREATE TABLE patient
(
treatement_id VARCHAR(255) PRIMARY KEY,
patient_id VARCHAR(255),
cost NUMBER
);

INSERT INTO patient
VALUES ('T001','P1500',55);

INSERT INTO patient
VALUES ('T003','P1500',NULL);

INSERT INTO patient
VALUES ('T004','P1500',57);

INSERT INTO patient
VALUES ('T005','P9500',NULL);

INSERT INTO patient
VALUES ('T006','P4000',81);

INSERT INTO patient
VALUES ('T007','P4000',82);

SELECT Nvl(cost,0),PATIENT_ID,TREATEMENT_ID
FROM patient;

SELECT *
FROM patient
WHERE cost < 60 OR cost >= 60;


SELECT LOWER(drug)
FROM treatment;

SELECT avg(salary)
FROM STAFF;

SELECT SUM(salary)
FROM staff;

SELECT MAX(t_time),MIN(t_time)
FROM treatment;

SELECT COUNT(t_time)
FROM treatment;

SELECT COUNT(drug)
FROM treatment
WHERE drug IS NOT NULL;