SQL在子查询中使用来自join的表

Question

我正在编写一个用作数据库 View 的查询，它现在看起来像这样:

SELECT
  contact.*,    
  contact_users.names AS user_names,
  contact_status.status_id AS status_id,
  status_translation.name AS status_name,
  status_translation.lang_id AS lang_id
FROM contacts as contact
LEFT JOIN contact_status AS contact_status ON contact_status.status_id = contact.status
LEFT JOIN contact_status_translation AS status_translation ON status_translation.id = contact.status
LEFT JOIN (
    SELECT
    contacts_users.contact_id,
      string_agg(users.fullname || ', ' || users.id, ' | ') as names  
  FROM v_contacts_users as contacts_users
  LEFT JOIN v_users as users on users.id = contacts_users.user_id
  WHERE users.lang_id = status_translation.lang_id
    GROUP BY contacts_users.contact_id
) AS contact_users ON contact_users.contact_id = contact.id  
WHERE contact.deleted = FALSE

除最后一个 LEFT JOIN 中的 WHERE 条件外，一切都按预期工作 - WHERE users.lang_id = status_translation.lang_id 部分表示status_translation 无法在这部分查询中引用？这是为什么？我尝试用各种方式引用此表，但结果仍然相同。v_users 也已翻译，因此我只需要从该表中获得一个结果。

Answer 1

如果您想引用以前的 FROM 列表条目，请在 LEFT JOIN 和左括号之间插入 LATERAL。