Sql 从多个不工作的表中检索数据

我有三张桌子

quiz:              activetruck:
id                 id   
name               name
origin             origin
destination        destination
total_trucks       total_trucks
material_type      scheduled_date
scheduled_date     offered_price
offered_price      owner_id
owner_id           subject_id
subject_id

我运行这个查询是为了从两个表中提取公共数据

Select * from quiz as cq, activetruck as ca
where cq.origin=ca.origin and cq.destination=ca.destination and 
cq.subject_id=ca.subject_id and cq.total_trucks<=ca.total_trucks;

我想获取供应商的所有详细信息，其中activetruck.owner\u id=suppliers.user\u id 我试着运行这个，但没用

Select * from classroom_quiz as cq, classroom_activetruck as ca, classroom_supplier as cs 
where cq.origin=ca.origin and cq.destination=ca.destination and
 cq.subject_id=ca.subject_id and cq.total_trucks<=ca.total_trucks and
 ca.owner_id=cs.user_id;

从课堂测验中选择*作为cq，课堂活动卡车作为ca，课堂供应商作为cs
其中cq.origin=ca.origin，cq.destination=ca.destination，且
cq.subject\u id=ca.subject\u id和cq.total\u您需要使用左外部连接。更多信息

activetruck和suppliers上的左侧外部联接将返回匹配的suppliers详细信息，但如果不匹配，则仍将返回activetruck行。您的查询正在加入activetruck匹配供应商的位置，但如果没有匹配，则不会返回任何内容

SELECT *
FROM classroom_quiz AS cq
INNER JOIN classroom_activetruck ca ON cq.origin = ca.origin
    AND cq.destination = ca.destination
    AND cq.subject_id = ca.subject_id
    AND cq.total_trucks <= ca.total_trucks
LEFT OUTER JOIN classroom_supplier cs ON ca.owner_id = cs.user_id;

选择*
作为cq参加课堂测验
cq.origin=ca.origin上的内部连接
和cq.destination=ca.destination
和cq.subject\u id=ca.subject\u id
和cq.total_卡车请不要使用不适用于您的问题的标签。我删除了数据库标签，因为不清楚您实际使用的是哪一个。请仅添加您实际使用的数据库的标记“它不工作”不是问题的准确描述。请详细说明。尝试使用连接
SELECT *
FROM classroom_quiz AS cq
INNER JOIN classroom_activetruck ca ON cq.origin = ca.origin
    AND cq.destination = ca.destination
    AND cq.subject_id = ca.subject_id
    AND cq.total_trucks <= ca.total_trucks
LEFT OUTER JOIN classroom_supplier cs ON ca.owner_id = cs.user_id;