PHP MySQL - IN / ALL / ANY子查询中的列'id'是不明确的

Question

我目前有以下查询工作：

$sql = $db->Query("SELECT a.id FROM surf a LEFT JOIN users b ON b.id = a.user LEFT JOIN surfed c ON c.user = '".$data['id']."' AND c.site = a.id WHERE a.active = '0' AND (b.coins >= a.cpc AND a.cpc >= '2') AND (c.site IS NULL AND a.user !='".$data['id']."')".$dbt_value." ORDER BY a.cpc DESC LIMIT 1");

但是我想在其中添加以下AND语句：

 AND `cpc`<='10' AND (`id` NOT IN (SELECT `site` FROM `surfed_site`)) 

所以我看起来像：

$sql = $db->Query("SELECT a.id FROM surf a LEFT JOIN users b ON b.id = a.user LEFT JOIN surfed c ON c.user = '".$data['id']."' AND c.site = a.id WHERE a.active = '0' AND (b.coins >= a.cpc AND a.cpc >= '2') AND `cpc`<='10' AND (`id` NOT IN (SELECT `site` FROM `surfed_site`)) AND (c.site IS NULL AND a.user !='".$data['id']."')".$dbt_value." ORDER BY a.cpc DESC LIMIT 1");

但接着我收到了这条消息：

IN / ALL / ANY子查询中的列'id'是不明确的

我的查询有什么问题？

Answer 1

尝试更改

AND `cpc`<='10' AND (`id` NOT IN (SELECT `site` FROM `surfed_site`)) 

到

AND `cpc`<='10' AND (`a.id` NOT IN (SELECT `site` FROM `surfed_site`)) 

您需要a.id，因为它不确定要在哪个表中引用id列。

Answer 2

出现该错误的原因是因为有多个表包含列ID。为了执行查询，您必须提供列ID所在的表，以便服务器识别哪个表与之相关，例如

AND `cpc`<='10' AND (a.`id` NOT IN (SELECT `site` FROM `surfed_site`)) 

如果您的意思是您要比较的ID来自表surf

Answer 3

您必须指定所需的id。 a.id，b.id等。

Answer 4

另外我假设$ data包含转义数据（单引号）？如果不是这是第二个问题。