如何将HQL子句（WHERE COUNT（）<MAX_VAL）添加到复杂查询

现在我的查询返回航班地图和其票数。我的目标是从查询结果(count(t) < f.aircraft.model.passengersSeatsQuantity)中排除完整航班。但我无法设法创建这样的查询。因此，现在我必须排除方法中的全部航班，这是令人沮丧的，因为我认为在查询中应该有办法做到这一点。任何人都可以帮助建立查询？附：我现在被允许使用Criteria API如何将HQL子句（WHERE COUNT（）<MAX_VAL）添加到复杂查询

String queryString = "SELECT f, COUNT(t)" 
      + " FROM Flight f" 
      + " JOIN FETCH f.tickets AS t" 
      + " WHERE f.departureAirport=:departureAirport" 
      + " GROUP BY t.flight" 
      + " ORDER BY f.id ASC"; 

Query query = em.createQuery(queryString); 
query.setParameter("departureAirport", departureAirport); 

Map<Flight, Long>) flightsTicketCountMap = 
      query.getResultList().stream() 
      .collect(Collectors.toMap(resultElement -> (Flight) (((Object[]) resultElement)[0]), 
        resultElement -> (Long) (((Object[]) resultElement)[1]))); 

//below i exclude full flights from map, but i want to do it in query 
Map<Flight, Long> availableFlightTicketPriceMap = new HashMap(); 
for (Map.Entry<Flight, Long> entry : flightsTicketCountMap.entrySet()) { 
     flight = entry.getKey(); 
     ticketsQuantity = entry.getValue(); 
     if (flight.getAircraft().getModel().getPassengersSeatsQuantity() > ticketsQuantity) { 
      availableFlightTicketPriceMap.put(flight, calculateTicketPrice(tariffsDetails, flight, ticketsQuantity)); 
     } 
    }

UPDATE。飞机和模型有跃跃欲试的政策，但HAVING COUNT(t) < f.aircraft.model.passengersSeatsQuantity有例外com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column aircraftmo3_.passenger_seats_quantity in having clause

public class Flight{ 
@OneToOne(fetch = FetchType.EAGER) 
@JoinColumn(name = "aircraft_id") 
    private Aircraft aircraft; 
} 

public class Aircraft{ 
    @ManyToOne(fetch = FetchType.EAGER) 
    @JoinColumn(name = "model_id") 
    private AircraftModel model; 
} 

public class AircraftModel{ 
    @Column(name = "passenger_seats_quantity") 
    @Range(min = 0, max = 450) 
    private Integer passengersSeatsQuantity; 
}

来源

2017-06-05 Yuriy Malikov

热加工您是否尝试过加入HAVING条款？

SELECT f, COUNT(t) 
FROM Flight f 
JOIN FETCH f.tickets AS t 
WHERE f.departureAirport=:departureAirport 
GROUP BY t.flight 
HAVING COUNT(t) < f.aircraft.model.passengersSeatsQuantity 
ORDER BY f.id ASC

来源

2017-06-05 06:32:11

我只是尝试，并得到com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException：在“having子句” 未知列“aircraftmo4_.passenger_seats_quantity”但飞机和模型有渴望获取的政策，所以比绑添加JOIN f.aircraft JOIN f.aircraft.model并且没有太大帮助（同样的例外）。嗯，怪异的行为 –

我很确定'HAVING'就是你想要的。您可能必须整理出您自己的HQL，并且在您能够掌握架构/实体之前，您最有可能做到这一点。 –

好的，谢谢！我会继续尝试使它工作。只是更新了我的问题与其他信息 –

如何将HQL子句（WHERE COUNT（）<MAX_VAL）添加到复杂查询

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