mysql加入兩個額外的列到查詢

Question

我有下面的sql。

CREATE TABLE states (
     id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, 
     name VARCHAR(255) 
    ) DEFAULT CHARACTER SET utf8 ENGINE=InnoDB; 

    CREATE TABLE teams (
     id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, 
     name VARCHAR(255), 
     stateid INT 
    ) DEFAULT CHARACTER SET utf8 ENGINE=InnoDB; 

    CREATE TABLE debates (
     id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, 
     debatedate DATE NOT NULL, 
     hostid INT, 
     visitid INT, 
     winnerid INT 
    ) DEFAULT CHARACTER SET utf8 ENGINE=InnoDB; 

    INSERT INTO states (id, name) VALUES 
    (1,'New York'), 
    (2,'Pennsylvania'), 
    (3,'Ohio'); 

    INSERT INTO teams (id, name, stateid) VALUES 
    (1,'team one',1), 
    (2,'team two',2), 
    (3,'team three',2), 
    (4,'team four',1), 
    (5,'team five',2), 
    (6,'team six',3); 

    INSERT INTO debates (id, debatedate,hostid, visitid, winnerid) VALUES 
    (1,'2012-01-11', 1,2,1), 
    (2,'2012-01-11', 3,4,4), 
    (3,'2012-02-11', 5,6,5), 
    (4,'2012-02-11', 1,4,1), 
    (5,'2012-02-11', 2,5,5), 
    (6,'2012-02-11', 3,6,3), 
    (7,'2012-03-11', 6,1,1), 
    (8,'2012-03-11', 5,2,5), 
    (9,'2012-03-11', 3,4,4); 

    SELECT deb.id, t1.name as Visitor , t2.name as Host 
    FROM debates AS deb 
    INNER JOIN teams t1 ON t1.id = deb.visitid 
    INNER JOIN teams t2 ON t2.id = deb.hostid 
    GROUP BY id 
    LIMIT 1 --Just have limit 1 to save space in the question 

它返回

----------------------------- 
    |ID |VISITOR |HOST  | 
    |1 |team two |team one | 
    ----------------------------- 

我也想回到什麼狀態辯論在。 舉行這個問題的答案將是主機標識的狀態。 在團隊表中有一個stateid列，但我無法使用它。

我試圖在參加

INNER JOIN teams t3 ON t3.id = states.id 

添加但是我得到的錯誤

Unknown column 'states.id' in 'on clause' 

我將如何去獲取這些信息。

我想回到

----------------------------------------- 
    |ID |VISITOR |HOST  |State  | 
    |1 |team two |team one |New York | 
    ----------------------------------------- 

see fiddle

Answer 1

你想

SELECT deb.id, t1.name as Visitor , t2.name as Host, s.name 
FROM debates AS deb 
INNER JOIN teams t1 ON t1.id = deb.visitid 
INNER JOIN teams t2 ON t2.id = deb.hostid 
inner join states s on t2.stateid = s.id 
GROUP BY id