Question

我有3张桌子 1项目
2项目ID，活动编号
3活动
我需要在这些表格中进行搜索，我试图使内部联接继续进行

1066 - 不唯一的表/别名：'pp086_projects'

我正在寻找“Next Nine”，这是在竞选活动中。

我的SQL查询是：

SELECT * FROM `PP086_projects`, `PP086_project_users`,pp086_project_companies
JOIN `PP086_projects` ON `PP086_projects`.id = pp086_project_companies.project_id
JOIN pp086_project_companies ON  pp086_companies.id==pp086_project_companies.company_id
WHERE (`PP086_projects`.`id` = `PP086_project_users`.`project_id`
       AND `PP086_project_users`.`user_id` = '2')
  AND ( name LIKE '%Next Nine%'
       OR name LIKE 'Next Nine'
       OR description LIKE 'Next Nine'
       OR pp086_project_companies.name LIKE 'Next Nine' )

Answer 1

您正在混合隐式和显式join语法。因此，您已将表PP086_projects放入from子句中两次。这可能是导致问题的原因。

作为一个简单的规则，只是不要在,子句中使用from。如果您想要交叉联接，请明确使用cross join：

SELECT *
FROM `PP086_projects` join
      `PP086_project_users`
      on `PP086_projects`.`id` = `PP086_project_users`.`project_id`
      pp086_project_companies
      ON `PP086_projects`.id = pp086_project_companies.project_id JOIN
      pp086_project_companies
      ON  pp086_companies.id = pp086_project_companies.company_id
WHERE (`PP086_project_users`.`user_id` = '2') AND
      ( name LIKE '%Next Nine%'
              OR name LIKE 'Next Nine'
              OR description LIKE 'Next Nine'
              OR pp086_project_companies.name LIKE 'Next Nine'
      );

Answer 2

您可以多次使用PP086_projects表。您应该为它的不同实例添加别名。这是不明确的，例如：PP086_projects.id

或者，如果这是无意的，可能你应该在FROM之后删除表的名称，如下所示：

      SELECT * FROM `PP086_projects`
      JOIN `PP086_project_users` ON `PP086_projects`.`id` = `PP086_project_users`.`project_id`
      JOIN `pp086_project_companies` ON `PP086_projects`.id = pp086_project_companies.project_id
      JOIN pp086_companies ON  pp086_companies.id== pp086_project_companies.company_id
       WHERE ( AND `PP086_project_users`.`user_id` = '2') AND ( name LIKE '%Next Nine%'
      OR name LIKE 'Next Nine'
      OR description LIKE 'Next Nine'
      OR pp086_project_companies.name LIKE 'Next Nine' )

我有一个SQL 1066 - 不唯一的表/别名：

2 个答案: