第 17.1 节：在具有相同名称的列上连接三个表

CREATE TABLE Table1 (
    id INT UNSIGNED NOT NULL,
    created_on DATE NOT NULL,
    PRIMARY KEY (id)
);

CREATE TABLE Table2 (
    id INT UNSIGNED NOT NULL,
    personName VARCHAR(255) NOT NULL,
    PRIMARY KEY (id)
);

CREATE TABLE Table3 (
    id INT UNSIGNED NOT NULL,
    accountName VARCHAR(255) NOT NULL,
    PRIMARY KEY (id)
);

创建表后，你可以执行一个 SELECT 查询来获取三个表中所有相同的 id：

SELECT
    t1.id AS table1Id,
    t2.id AS table2Id,
    t3.id AS table3Id
FROM Table1 t1
LEFT JOIN Table2 t2 ON t2.id = t1.id
LEFT JOIN Table3 t3 ON t3.id = t1.id;