SQL ORA-00979錯誤拋出

我想創建一個查詢，返回一個事物的名稱和國家在另一個表中的最大次數。SQL ORA-00979錯誤拋出

這裏的結構：

ShipModels(mname, type, country, numGuns, gunSize) 
Ships(sname, hasModel, launchYear) 
Battles(bname, year) 
Outcomes(ship, battle, result)

我已經嘗試了很多不同的東西，但不能讓它開始工作。這是我當前的查詢：

SELECT ship, country 
FROM ShipModels, Ships, Outcomes 
WHERE hasModel = mname AND ship = sname 
GROUP BY ship 
HAVING COUNT(ship) >= 
(SELECT COUNT (ship) FROM Outcomes GROUP BY ship);

Oracle錯誤：

ERROR at line 1: 
ORA-00979: not a GROUP BY expression

從我已閱讀，當出現在SELECT語句的聚合函數將引發此錯誤，但是... ... ，沒有。有什麼我失蹤？我怎樣才能使這個工作？

來源

2012-12-03 Devon Roberts

如果你打算使用具有COUNT（船），我相信你需要包括COUNT（船）在你的SELECT – WebChemist

你包括在SELECT的country：

SELECT ship, country

但不是在GROUP BY。更改該行：

GROUP BY ship, country

當你改正，你會碰到另一個錯誤，因爲子查詢是不標，例如不返回一個值：

(SELECT COUNT (ship) FROM Outcomes GROUP BY ship)

你大概意思寫：

(SELECT MAX(cnt) 
    FROM 
    (SELECT COUNT(ship) AS cnt FROM Outcomes GROUP BY ship) t 
)

所以，完整的查詢將或多或少：

SELECT ship, country 
FROM ShipModels, Ships, Outcomes 
WHERE hasModel = mname AND ship = sname 
GROUP BY ship, country 
HAVING COUNT(ship) = 
    (SELECT MAX(cnt) 
     FROM 
     (SELECT COUNT(ship) AS cnt FROM Outcomes GROUP BY ship) t 
    ) ;

你也可以把它寫更像你的企圖，使用關鍵字ALL：

SELECT ship, country 
FROM ShipModels, Ships, Outcomes 
WHERE hasModel = mname AND ship = sname 
GROUP BY ship, country 
HAVING COUNT(ship) >= ALL 
    (SELECT COUNT(ship) AS cnt FROM Outcomes GROUP BY ship) ;

如果您使用顯式連接的「現代」（SQL-92）語法，這也會很好。相反的：

FROM ShipModels, Ships, Outcomes 
WHERE hasModel = mname AND ship = sname

這是因爲各種原因更好地寫出：

FROM ShipModels m 
    JOIN Ships s ON s.hasModel = m.mname 
    JOIN Outcomes o ON o.ship = s.sname

來源

2012-12-03 01:34:21

正是我在找什麼！非常感謝你！ –

問題在於HAVING子句中的計數（發貨）。我認爲這是select語句中的聚合函數。

來源

2012-12-03 00:17:43 kdmurray

SQL ORA-00979錯誤拋出

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