在JPA查询中使用GROUP BY / HAVING子句

Question

我有两个与父母/孩子一对多关系的课程：

父母：

@Entity 
@Table(name="RMS.COMMITMENT_REGISTER")
public class CommitmentRegister {

    @Id
    @Column(name="COMMIT_REG_ID")
    private int id;

    @OneToMany(fetch=FetchType.EAGER)
    @JoinColumn(name="COMMIT_REG_ID")
    private List<CommitmentRegisterDetail> details;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public List<CommitmentRegisterDetail> getDetails() {
        return details;
    }

    public void setDetails(List<CommitmentRegisterDetail> details) {
        this.details = details;
    }

}

和孩子：

@Entity 
@Table(name="RMS.COMMITMENT_REGISTER_DETAIL")
public class CommitmentRegisterDetail {

    @Id
    @Column(name="COMMIT_REG_DETAIL_ID")
    private int id;

    @Column(name="AMOUNT")
    private BigDecimal amount;

    @ManyToOne(fetch=FetchType.EAGER)
    @JoinColumn(name="COMMIT_REG_ID")
    private CommitmentRegister commitmentRegister;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public BigDecimal getAmount() {
        return amount;
    }

    public void setAmount(BigDecimal amount) {
        this.amount = amount;
    }

    public CommitmentRegister getCommitmentRegister() {
        return commitmentRegister;
    }

    public void setCommitmentRegister(CommitmentRegister parent) {
        this.commitmentRegister = parent;
    }

}

我想查询详细信息总数超过100的CR。我正在使用以下查询：

    StringBuffer sql = new StringBuffer();

    sql.append( " SELECT CR " );
    sql.append( " FROM CommitmentRegister CR " );
    sql.append( " LEFT JOIN CommitmentRegisterDetail CRD ON ( CRD.commitmentRegister = CR ) ");
    sql.append( " WHERE CR.id >= 91000 " );

    sql.append( " GROUP BY CR " );

    sql.append( " HAVING SUM( CRD.amount ) > 100 " );

    Query q = em.createQuery( sql.toString() );

    return q.getResultList();

但是我收到以下错误：

Local Exception Stack: 
Exception [EclipseLink-6015] (Eclipse Persistence Services - 2.4.1.v20121003-ad44345): org.eclipse.persistence.exceptions.QueryException
Exception Description: Invalid query key [amount] in expression.
Query: ReportQuery(referenceClass=CommitmentRegister jpql=" SELECT CR  FROM CommitmentRegister CR  LEFT JOIN CommitmentRegisterDetail CRD ON ( CRD.commitmentRegister = CR )  WHERE CR.id >= 91000  GROUP BY CR  HAVING SUM( CRD.amount ) > 100 ")

在没有HAVING行的情况下，查询运行良好，并且将正确的详细信息分配给了父（CR）。

提前致谢。

表结构（如果相关）

COMMITMENT_REGISTER
    COMMIT_REG_ID

COMMITMENT_REGISTER_DETAIL
    COMMIT_REG_DETAIL_ID
    COMMIT_REG_ID
    AMOUNT

Answer 1

我的猜测是，与HAVING相比，它对连接的处理更多，因为HAVING应该根据EclipseLink文档工作 。

也许尝试这样的事情，看看进展如何：

StringBuffer sql = new StringBuffer();

sql.append( " SELECT CR " );
sql.append( " FROM CommitmentRegisterDetail CRD " );
sql.append( " LEFT JOIN CRD.commitmentRegister CR ");
sql.append( " WHERE CR.id >= 91000 " );
sql.append( " GROUP BY CRD.commitmentRegister " );
sql.append( " HAVING SUM( CRD.amount ) > 100 " );

Query q = em.createQuery( sql.toString() );

return q.getResultList();