MySQL 8.0

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CREATE TABLE Hospital ( id int, hospital_name varchar(20), address varchar(20), city_id int )
INSERT INTO Hospital (id, hospital_name, address, city_id)
SELECT 1, 'pars', '55,6LA', 2 UNION ALL
SELECT 2, 'ghaem', '12.9GI', 2 UNION ALL
SELECT 3, 'Mehr', '632.Sp', 2 UNION ALL
SELECT 4, 'Erfan', '21,6UJ', 3 UNION ALL
SELECT 5, 'Razavi', '31.jjI', 3 UNION ALL
SELECT 6, 'Mohab', '65.Spi', 1
CREATE TABLE Cities (id int, cityname varchar(20))
INSERT INTO Cities (id, cityname)
SELECT 1, 'LosAngeles' UNION ALL
SELECT 2, 'NewYork' UNION ALL
SELECT 3, 'California'
CREATE TABLE Treatments (id int, TreatmentName varchar(50))
INSERT INTO Treatments (id, TreatmentName)
SELECT 1, 'nose surgery' UNION ALL
SELECT 2, 'Orthopedic' UNION ALL
SELECT 3, 'Knee joint replacement'
CREATE TABLE treatment_prices (id int, Treatments_id int, Hospital_id int, Price int)
INSERT INTO treatment_prices (id, Treatments_id, Hospital_id, Price)
SELECT 1,1,1,700 UNION ALL
SELECT 2,1,6,800 UNION ALL
SELECT 3,1,4,900 UNION ALL
SELECT 4,2,1,500 UNION ALL
SELECT 5,2,2,700 UNION ALL
SELECT 6,2,3,300 UNION ALL
SELECT 7,3,1,600 UNION ALL
SELECT 8,3,2,450
SELECT s1.TreatmentName, s1.Hospital_Name, s1.Price
FROM (
    SELECT t.TreatmentName, h.Hospital_Name, tp.Price
        , ROW_NUMBER() OVER (PARTITION BY tp.Treatments_ID ORDER BY tp.Price) AS rn
    FROM treatment_prices tp 
    INNER JOIN Hospital h ON tp.Hospital_ID = h.ID
    INNER JOIN Cities c ON h.city_id = c.id
            AND c.ID = 2
    INNER JOIN Treatments t ON tp.Treatments_ID = t.ID
) s1
WHERE rn = 1
;


TreatmentName
Hospital_Name
Price


nose surgery
pars
700

Orthopedic
Mehr
300

Knee joint replacement
ghaem
450

TreatmentName	Hospital_Name	Price
nose surgery	pars	700
Orthopedic	Mehr	300
Knee joint replacement	ghaem	450