hibernate - JPA 计数查询以按查询计算组的总结果行

Question

如何在 JPQL 中获取 SQL 查询下面的总结果行:

select
        count(usertransa0_.id) as col_0_0_ 
    from
        user_transaction usertransa0_ cross 
    join
        merchant_master merchantma1_ 
    where
        usertransa0_.merchant_master=merchantma1_.id 
        and usertransa0_.status=0 
        and (
            usertransa0_.transaction_date between '2015-02-19' and '2015-02-20'
        ) 
    group by
        merchantma1_.full_name;

我试过:

SELECT COUNT(ut)
    FROM UserTransaction ut 
    WHERE ut.status = :stus AND ut.transactionDate between :frm AND :toDt"
    GROUP BY ut.merchantMaster.fullName

但它只返回第一行数，如何获得总行数？

编辑:

我的实体看起来像:

public class UserTransaction extends BaseEntity {

    @OneToOne(fetch = FetchType.LAZY)
    private UserInfo info;

    @OneToOne(fetch = FetchType.LAZY)
    private MerchantMaster merchantMaster;

    @OneToOne(fetch = FetchType.LAZY)
    private PaymentMaster paymentMaster;

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

    @Temporal(TemporalType.TIMESTAMP)
    @Column(name = "TRANSACTION_DATE")
    private Date transactionDate;

    @Column(name = "STATUS")
    private Integer status;

    private String userTransactionID;

    @OneToOne(cascade = { CascadeType.ALL }, fetch = FetchType.LAZY)
    private UserTransactionRequest trRequest;

    @OneToOne(cascade = { CascadeType.ALL }, fetch = FetchType.LAZY)
    private UserTransactionResponse trResponse;

    //getters & setters
}   

Answer 1

您的查询将返回一个 Long 数组。每个 Long 是给定 MerchantMaster 名称的 UserTransaction 的计数。

如果您在 NamedQuery 中有您的查询，您可以使用(如果没有，您可以使用 creatyQuery() 方法并使用您的 JPQL 查询字符串):

TypedQuery<Long> query = em.createNamedQuery("UserTransaction.MyQuery", Long.class);
/* The list have the count of User Transaction grouped by Merchant name */
List<Long> userTransactionsPerMerchantName = query.getResultList();

您可能还需要商家名称，您可以将商家名称添加到您的查询中:

SELECT COUNT(ut), ut.merchantMaster.fullName
FROM UserTransaction ut 
WHERE ut.status = :stus AND ut.transactionDate between :frm AND :toDt"
GROUP BY ut.merchantMaster.fullName

现在，查询将返回一个对象数组，第一个对象是计数，第二个是名称。您还需要修改代码以获取结果:

TypedQuery<Object[]> query = em.createNamedQuery("UserTransaction.MyQuery", Object[].class);
List<Object []> results = query.getResultList();
for (Object [] row : results) {
    Long count = (Long) row[0];
    String name = (String) row[1];
}