在ON子句另一個未知的列名錯誤

Question

查詢：

SELECT c.title AS title 
      , c.introtext AS body 
      , c.state AS state 
      , c.created AS created 
      , c.created_by AS uid 
      , c.modified AS modified 
      , c.modified_by AS modified_uid 
      , c.published AS published 
      , c.published_by AS published_uid 
      , jos_categories.title AS category 
FROM 
      jos_content AS c, jos_categories 
INNER JOIN jos_categories AS jc 
ON c.sectionid = jc.section 
WHERE c.sectionid = 7 

我相信sectionid柱存在，但我得到的錯誤：

Error Code: 1054. Unknown column 'c.sectionid' in 'on clause' 0.000 sec

我看到這個題目：MySQL unknown column in ON clause但我可以也解決不了。

Answer 1

改變你的FROM子句：

FROM jos_content AS c 
INNER JOIN jos_categories AS jc 
ON c.sectionid = jc.section 
WHERE c.sectionid = 7 

Answer 2

您瓶坯加入jos_categories和jos_categories AS jc之間：

jos_content AS c, jos_categories 
INNER JOIN jos_categories AS jc 
ON c.sectionid = jc.section 

但c是jos_content ...