NamedQuery 返回具有空字段的实体

Question

使用 namedquery 定义的实体为 SELECT mdl FROM tbl_slots mdl where mdl.test_date between :dt and :dt order by mdl.test_time asc

如果在查询中使用 * 而不是 mdl，JPA 会给出错误 unexpected token: *

如果在 select 语句中提到列名，则 returns 实体的各个字段填充了预期值

[{ "srNo": 1, "testDate": "2021-Dec-30", "testTime": "09:00-10:00", },{ "srNo": 2, "testDate": "2021-Dec-30", "testTime": "11:00-12:00", }]

如何在不在 select 语句中提及列名的情况下获得与使用 *? 相同的结果

select * from table 查询的有效 JPQL 或 HQL 是什么？

实体class

@Table(name = "tbl_slots")
@NamedQueries({
    @NamedQuery(name="slots",query = "SELECT mdl FROM tbl_slots mdl where  mdl.test_date between :dt and :dt order by mdl.test_time asc")
})
public class TblSlots implements Serializable {
    private Long srNo;
    private Date testDt;
    private String testTime;
        
    public TblSlots() {}
    public TblSlots(Long srNo, Date testDt, String testTime) {
        this.srNo = srNo;
        this.testDt = testDt;
        this.testTime = testTime;
    }
    
    @Id
    @Column(name = "sr_no", unique = true, nullable = false, precision = 16, scale = 0)
    public Long getSrNo() {
        return this.srNo;
    }

    public void setSrNo(Long srNo) {
        this.srNo = srNo;
    }

    @Temporal(TemporalType.DATE)
    @Column(name = "test_date", nullable = false, length = 13)
    public Date getTestDt() {
        return this.testDt;
    }

    public void setTestDt(Date testDt) {
        this.testDt = testDt;
    }

    @Column(name = "test_time", nullable = false, length = 20)
    public String getTestTime() {
        return this.testTime;
    }

    public void setTestTime(String testTime) {
        this.testTime = testTime;
    }

Answer 1

你不能使用'*'，因为Hibernate 正在转动对象。如果要使用 *，请使用 @NamedNativeQuery 而不是 @NamedQuery

@NamedQueries({
    @NamedQuery(name="slots",query = "SELECT mdl FROM Member mdl ")
})
// Use this
@NamedNativeQueries({
    @NamedNativeQuery(name="slots_native",query = "SELECT * FROM Member mdl ",resultClass = MemberEntity.class)
})

引用@NamedNativeQuery

Answer 2

JPQL 理解 java 个实体而不是列。

how to get same result without mentioning column names in select statement as if used *?

what's valid JPQL or HQL for select * from table query?

所以一个有效的 JQPL SELECT 查询甚至可以没有 SELECT 子句。

以下是对 return 来自 table

的完整实体的有效 JPQL 查询

FROM tbl_slots mdl where  mdl.test_date between :dt and :dt order by mdl.test_time asc

所以你的注释可以写成

@NamedQueries({
    @NamedQuery(name="slots",query = "FROM tbl_slots mdl where  mdl.test_date between :dt and :dt order by mdl.test_time asc")
})

NamedQuery 返回具有空字段的实体

NamedQuery returning entities with null fields

java

orm

hibernate

spring-data-jpa

spring-boot