mysql - 我有一个 SQL 1066 - 不唯一的表/别名 :

Question

我有3张 table
1个项目
2 项目 ID、事件 ID
3 个事件
我需要对所有这些表连接进行搜索，我试图进行内部连接，我不断得到

1066 - Not unique table/alias: 'pp086_projects'

我正在搜索事件中的“下九个”。

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。这可能是导致您出现问题的原因。

作为一个简单的规则，只需不要在 from 子句中使用 , 即可。如果您想要交叉联接，请显式使用交叉联接:

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'
      );