Php 如何从重复行检查MYSQL连接中的一个特定结果

我试图使用id从另一个表的联接中检查特定记录，但另一个表有多个具有相同id的记录。我想选择列中没有所有人的记录

我的SQL是：

SELECT b.*
     , a.* 
  FROM engine4_blog_blogs b
  LEFT 
  JOIN engine4_authorization_allow a
    ON a.resource_id = b.blog_id 
 WHERE a.resource_type = 'blog'
   AND a.role NOT IN ('everyone')
   AND a.action = 'view'
   AND b.draft = 0
   AND b.search = 1
 ORDER 
    BY b.creation_date DESC 

我只想选择记录没有所有人，只选择一行不重复

blog 2 view everyone            0 1 NULL
blog 2 view owner_member        0 1 NULL
blog 2 view owner_member_member 0 1 NULL
blog 2 view owner_network       0 1 NULL
blog 2 view registered          0 1 NULL

---

谢谢，

如果要选择没有“everyone”的行，需要将第二个表中的所有条件移动到

on

子句中：

SELECT b.*, a.* 
FROM engine4_blog_blogs b LEFT JOIN
     engine4_authorization_allow a
     ON a.resource_id = b.blog_id AND
        a.resource_type = 'blog' AND
        a.role IN ('everyone') AND
        a.action = 'view'
WHERE b.draft = 0 AND b.search = 1 AND a.resource_id IS NULL
ORDER BY b.creation_date DESC ;

如果在

WHERE

子句中放入条件，它会过滤掉所有不匹配的行，将

左连接

转换为

内部连接

尝试：

SELECT DISTINCT b.*, a.* 
  FROM engine4_blog_blogs b
  LEFT 
  JOIN engine4_authorization_allow a
  ON a.resource_id = b.blog_id 
  WHERE  a.resource_type = 'blog'
  AND a.action = 'view'
  AND a.role NOT IN ('everyone')
  AND b.draft = 0
  AND b.search = 1
  AND a.resource_id IS NULL
  ORDER BY b.creation_date DESC 

---

您可以使用distinct命令来避免重复记录

SELECT DISTINCT b.*
     , a.* 
  FROM engine4_blog_blogs b
  LEFT 
  JOIN engine4_authorization_allow a
    ON a.resource_id = b.blog_id 
 WHERE a.resource_type = 'blog'
   AND a.role NOT IN ('everyone')
   AND a.action = 'view'
   AND b.draft = 0
   AND b.search = 1
 ORDER 
    BY b.creation_date DESC 

---

你知道呈现为内部连接，对吗？是的，但我只想从包含everyone的查询nit中获取一条记录，而不是多条记录。现在它显示了一条记录的重复行。太好了！谢谢你的魅力！我不知道为什么人们会否决我的问题？