ORA-01791：不是SELECTed表达式

Question

我需要从DB获取详细信息。我的代码中有什么问题吗？

SELECT DISTINCT FNAME, LNAME, MEMBERORG, DAYCOUNT, TIMESTAMP, COUNT(FNAME) AS total,(SELECT COUNT(*) FROM REPORT_VIEW_PAGE) AS tot
FROM REPORT_VIEW_PAGE 
WHERE ID = '68' AND TYPE = 'node'
GROUP BY FNAME, LNAME, MEMBERORG, DAYCOUNT, TIMESTAMP
ORDER BY TITLE ASC

这给了我一个错误：

ORA-01791: not a SELECTed expression
01791. 00000 -  "not a SELECTed expression"
*Cause:    
*Action:
Error at Line: 6 Column: 10

Answer 1

此处的问题是在ORDER BY查询中未选择TITLE列DISTINCT。由于使用了DISTINCT，SELECT查询会尝试根据所选列对resultset进行分组。

此处未选择

ORDER BY列，它不会确保resultset的唯一性，因此无法应用ORDER BY。

Answer 2

SELECT DISTINCT FNAME, LNAME, MEMBERORG, DAYCOUNT, TIMESTAMP, total, tot
FROM
(
SELECT DISTINCT FNAME, LNAME, MEMBERORG, DAYCOUNT, TIMESTAMP, COUNT(FNAME) AS total,(SELECT COUNT(*) FROM REPORT_VIEW_PAGE) AS tot
FROM REPORT_VIEW_PAGE 
WHERE ID = '68' AND TYPE = 'node'
GROUP BY FNAME, LNAME, MEMBERORG, DAYCOUNT, TIMESTAMP
ORDER BY TITLE ASC
)