通过MAX（）进行SQL搜索

您有几种选择

SELECT DOC_NAME FROM DOCUMENTS WHERE DELIVERY_TIMESTAMP IN ( SELECT MAX(DELIVERY_TIMESTAMP) FROM DOCUMENTS ) 或加入

SELECT DOC_NAME FROM DOCUMENTS INNER JOIN ( SELECT MAX(DELIVERY_TIMESTAMP) AS MAX_DELIVERY_TIMESTAMP FROM DOCUMENTS ) AS M ON M.MAX_DELIVERY_TIMESTAMP = DOCUMENTS.DELIVERY_TIMESTAMP 如果时间戳中有重复项，或者您在“最大”条件中需要多个列（因为MAX()所有行仅在一个列上），它将变得更加复杂。

在这里，该JOIN选项是唯一可用的选项，因为这样的构造不可用（例如具有相同时间戳的多个订单）：

SELECT DOC_NAME FROM DOCUMENTS WHERE (DELIVERY_TIMESTAMP, ORDERID) IN ( SELECT TOP 1 DELIVERY_TIMESTAMP, ORDERID FROM DOCUMENTS ORDER BY DELIVERY_TIMESTAMP DESC, ORDERID DESC ) 实际上，您需要执行以下操作：

SELECT DOC_NAME FROM DOCUMENTS INNER JOIN ( SELECT TOP 1 DELIVERY_TIMESTAMP, ORDERID FROM DOCUMENTS ORDER BY DELIVERY_TIMESTAMP DESC, ORDERID DESC ) AS M ON M.DELIVERY_TIMESTAMP = DOCUMENTS.DELIVERY_TIMESTAMP AND M.ORDERID = DOCUMENTS.ORDERID