將SQL語句轉換為JPQL語句

Question

我想知道如何將此SQL語句轉換為JPQL：

SELECT sum(price) AS Income, count(*) AS Passages, Station.Name 
FROM Passage
INNER JOIN station ON passage.stationId = station.id
GROUP BY Station.Name

不會是這樣的：

SELECT sum(price) AS Income, count(p) AS Passages, s.Name FROM Passage p
INNER JOIN station s     
ON p.stationId = s.id GROUP BY s.Name

？

Answer 1

問題解決了：

SELECT count(p), sum(p.price), s 
FROM Passage p 
INNER JOIN p.station s 
GROUP BY s.name;

Answer 2

JPQL （JPA 2.0）中沒有ON ，但您可以執行隱式連接並使用WHERE子句：

假設實體Passage atriburo StationID是與實體Station的屬性id相同的對象類型。

SELECT SUM(s.price) Income, COUNT(p) Passages, s.Name
FROM Passage p, Station s
WHERE p.stationId = s.id
GROUP BY s.Name

建議如果問題可以添加實體Station Passage並給出正確的答案。