mysql - #1054 - 't2.id_pro' 中的未知列 'where clause'

Question

我有以下查询:

SELECT 
    t1.name as tipo, t1.id as id_tracker,
    t2.name as nombre_pro, t2.id as id_pro, 
    t3.project_id as pro_tra_id, t3.tracker_id as id_pro_tra_id2 
FROM trackers t1, projects t2, projects_trackers t3 
WHERE t2.id_pro=t3.pro_tra_id and 
    t1.id_tracker=t3.id_pro_tra_id2 and
    t3.pro_tra_id=1

但同样会引发以下错误:

#1054 - Unknown column 't2.id_pro' in 'where clause'

我真的不明白如果有人可以帮助我，我将不胜感激!

Answer 1

试试这个:

SELECT 
t1.name as tipo, t1.id as id_tracker,
t2.name as nombre_pro, t2.id as id_pro, 
t3.project_id as pro_tra_id, t3.tracker_id as id_pro_tra_id2 
FROM 
trackers t1, projects t2, projects_trackers t3 
WHERE t2.id = t3.project_id 
AND t1.id = t3.tracker_id 
AND t3.project_id=1

如果您使用SELECT t1.name as tipo，您可以使用tipo或t1.name，但不能 t1.tipo。另外，我不相信您可以在 WHERE 子句中使用别名。