mysql三级联动查询

-- 创建表
CREATE TABLE province (
    id INT PRIMARY KEY,
    name VARCHAR(50)
);

CREATE TABLE city (
    id INT PRIMARY KEY,
    name VARCHAR(50),
    province_id INT,
    FOREIGN KEY (province_id) REFERENCES province(id)
);

CREATE TABLE district (
    id INT PRIMARY KEY,
    name VARCHAR(50),
    city_id INT,
    FOREIGN KEY (city_id) REFERENCES city(id)
);

-- 插入示例数据
INSERT INTO province (id, name) VALUES (1, '广东省');
INSERT INTO city (id, name, province_id) VALUES (1, '广州市', 1);
INSERT INTO district (id, name, city_id) VALUES (1, '天河区', 1);

-- 三级联动查询
SELECT 
    p.name AS province_name,
    c.name AS city_name,
    d.name AS district_name
FROM 
    province p
INNER JOIN 
    city c ON p.id = c.province_id
INNER JOIN 
    district d ON c.id = d.city_id;