Mysql 1054-on子句中的未知列“purchasedetail.itemId”

尝试获取此记录时，purchasedetail表中出现错误。这是我的选择查询：

SELECT itemstock.itemId
  FROM  itemstock
  JOIN item ON item.itemId = purchasedetail.itemId
  JOIN purchasemaster ON purchasemaster.purchaseMasterId = purchasedetail.purchaseMasterId
  JOIN purchasedetail ON purchasedetail.itemId = item.itemId
  JOIN party ON party.partyId = purchasemaster.partyId
WHERE
  purchasemaster.partyId = ".$_REQUEST['partyId']."
  AND itemstock.quantity > 0
GROUP BY itemName,itemCode

这就是错误：

#1054 - Unknown column 'purchasedetail.itemId' in 'on clause'

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在联接表时，联接的列必须属于这些表。您正在尝试连接其他表中尚未提到的列。试试这个：

SELECT itemstock.itemId 
FROM itemstock 
JOIN item ON item.itemId = itemstock.itemId 
JOIN purchasedetail ON purchasedetail.itemId = item.itemId 
JOIN purchasemaster ON purchasemaster.purchaseMasterId = purchasedetail.purchaseMasterId 
JOIN party ON party.partyId = purchasemaster.partyId 
WHERE purchasemaster.partyId = 5 AND itemstock.quantity > 0 GROUP BY itemName,itemCode

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表purchasedetail是否有一个名为itemId的列？不是吗？这就是为什么它是一个未知列-正如错误所说。您在FROM子句中有itemstock，但它似乎没有与任何其他表联接。您是否缺少item和itemstock之间的联接？好的，所以我必须联接itemstock alsoyes purchasedetail have itemId column@h2ooooooo