Java Spring 休眠 HQL where 子句不起作用

Question

我有一個帶有 JOIN 的 HQL 查詢，但連接實體上的 where 子句 (instrPrice.date BETWEEN :dateFrom AND :dateTo ) 不起作用。 查詢始終返回 instrumentPrice 的所有記錄，而不是按日期限制結果。

命名查詢

@NamedQuery(name = "findAllPrices", 
        query = "SELECT DISTINCT taPat FROM TaPatternInstrument taPat "
                + "LEFT JOIN FETCH taPat.instrument instr "
                + "LEFT JOIN instr.instrumentPriceList instrPrice "
                + "WHERE taPat.id = :taPatternInstrumentId "
                + "AND instrPrice.date BETWEEN :dateFrom AND :dateTo ")

調用查詢的服務

public TaPatternInstrument findAllPrices(int taPatternInstrumentId, LocalDate dateFrom,  LocalDate dateTo) {

   TypedQuery<TaPatternInstrument> typedQuery = createNamedQuery("findAllPrices", 
        TaPatternInstrument.class);
   typedQuery.setParameter("taPatternInstrumentId", taPatternInstrumentId);
   typedQuery.setParameter("dateFrom", dateFrom);
   typedQuery.setParameter("dateTo", dateTo);
   return typedQuery.getSingleResult(); 
}

實體

public abstract class BaseEntity implements Serializable {

   @Id  
   @Column(name = "id")     
   @GeneratedValue(strategy =
                GenerationType.IDENTITY)
   protected int id; ... 
}

public class TaPatternInstrument extends BaseEntity {

   @ManyToOne(fetch = FetchType.EAGER)
   @JoinColumn(name = "instrument_id", nullable = false, foreignKey = @ForeignKey(name = 
            "tapatterninstrument_instrument_fk"))
   private Instrument instrument;

}


public class Instrument extends BaseEntity {

  @OneToMany(mappedBy = "instrument", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
  private List<InstrumentPrice> instrumentPriceList;

}

生成的 SQL

SELECT DISTINCT tapatterni0_.id  AS id1_34_0_, 
...
FROM   tapatterninstrument tapatterni0_ 
       LEFT OUTER JOIN instrument instrument1_ 
                    ON tapatterni0_.instrument_id = instrument1_.id 
       LEFT OUTER JOIN instrumentprice instrument2_ 
                    ON instrument1_.id = instrument2_.instrument_id 
WHERE  tapatterni0_.id = ? 
       AND ( instrument2_.date BETWEEN ? AND ? ) 

Answer 1

解決方案是在 instrumentPriceList 上添加一個 FETCH ： LEFT JOIN FETCH instr.instrumentPriceList instrPrice

@NamedQuery(name = "findAllPrices", 
query = "SELECT DISTINCT taPat FROM TaPatternInstrument taPat "
        + "LEFT JOIN FETCH taPat.instrument instr "
        + "LEFT JOIN FETCH instr.instrumentPriceList instrPrice "
        + "LEFT JOIN taPat.taPatternInstrumentPriceList taPatpr "
        + "WHERE taPat.id = :taPatternInstrumentId "
        + "AND instrPrice.date BETWEEN :dateFrom AND :dateTo ")

FETCH 強制 Hibernate 在第一個 DB 請求時立即檢索實體 (InstrumentPrice)。 因此考慮了 where 子句。 如果沒有 FETCH，則只有在調用實體工具的方法 getInstrumentPriceList 時才從數據庫中檢索實體工具價格（執行對數據庫的額外調用）。 並且通過對數據庫的這個額外調用，不再考慮 where 子句，從而從實體 instrumentPrice 檢索所有記錄。