spring jpa @Query 错误，期待 CLOSE，发现 '('答案

【问题标题】：spring jpa @Query 错误，期待 CLOSE，发现 '('
【发布时间】：2022-01-23 16:53:52
【问题描述】：

我有一个运行良好的以下 mysql 查询：

*编辑：路径仅用于说明目的...我不想复制我的包...

select COUNT(IF(amount > 0, amount, 0)) as creditCount,
       COUNT(IF(amount < 0, amount, 0)) as debitCount,
       SUM(IF(amount > 0, amount, 0)) as credit,
       SUM(IF(amount < 0, amount, 0)) as debit,
       SUM(amount)                    as balance,
       cp.surname, cp.id, pcp.number from prepaid_card_transaction_pojo pctp
         join prepaid_card_pojo pcp on pctp.account = pcp.id
         join customer_pojo cp on pcp.id = cp.prepaid_card
where pcp.number = '1000765352' AND pctp.client = UUID_TO_BIN('fb9dbcac-cd03-46ad-94b0-2709b0b0e2a8') AND booking_time > '2020-12-01 00:00:00' group by cp.id;

我想转给jpql：

@Query("select new path...Bean(" + //
            "COUNT(IF(pctp.amount > 0, pctp.amount, 0))," + //
            "COUNT(IF(pctp.amount < 0, pctp.amount, 0)), " + //
            "SUM(IF(pctp.amount > 0, pctp.amount, 0)), " + //
            "SUM(IF(pctp.amount < 0, pctp.amount, 0)), " + //
            "SUM(pctp.amount), cp) " + //
            "FROM PrepaidCardTransactionPojo pctp " + //
            "JOIN PrepaidCardPojo pcp ON pctp.account = pcp.id " + //
            "JOIN CustomerPojo cp ON pcp.id = cp.prepaid_card " + //
            "WHERE pcp.number =:voucherNumber AND pctp.client =:client AND booking_time >= :from AND booking_time < :to GROUP BY :customer")
    List<Bean> loadGroupedCustomerPrepaidTransactions(@Param("client") ClientReadable client, @Param("customer") CustomerReadable customer, @Param("voucherNumber") String voucherNumber, @Param("from") Date from, @Param("to") Date to);

我收到以下错误： ...QuerySyntaxException: expecting CLOSE, found '(' near...

【问题讨论】：

你认为这是正确的新路径吗...Bean(........
@RaushanKumar 我认为他写 Bean 是为了简单起见。

标签： java spring spring-data jpql

【解决方案1】：

感谢您的回答。经过几个小时的调整，以下是经验教训：

JPQL 不喜欢列别名...
JPQL 不喜欢 IF（正在使用 “COUNT(IF(pctp.amount > 0, pctp.amount, 0))”，应该使用： "COUNT(当 pctp.amount > 0 then 1 else 0 end),"
JPQL COUNT 应该使用数字作为匹配计数的次数 - 上面示例中的特定 1。而 mysql 只是将条件匹配值设为 1
所有列出的属性都应该来自 pojo 指定而不是 DB 列指定，就像我在最初的帖子中所做的那样，以防 cp.prepaid_card

【讨论】：

【解决方案2】：

试着喜欢这个：

@QUERY(nativeQuery = true, value = "select COUNT(IF(amount > 0, amount, 0)) as creditCount,
       COUNT(IF(amount < 0, amount, 0)) as debitCount,
       SUM(IF(amount > 0, amount, 0)) as credit,
       SUM(IF(amount < 0, amount, 0)) as debit,
       SUM(amount)                    as balance,
       cp.surname, cp.id, pcp.number from prepaid_card_transaction_pojo pctp
         join prepaid_card_pojo pcp on pctp.account = pcp.id
         join customer_pojo cp on pcp.id = cp.prepaid_card
where pcp.number = :voucherNumber AND pctp.client = :client AND booking_time > :from AND booking_time < :to group by cp.id)
List<Bean> loadGroupedCustomerPrepaidTransactions( ClientReadable client,  CustomerReadable customer,  String voucherNumber, Date from, Date to);

【讨论】：

【解决方案3】：

尝试添加nativeQuery = true，表示查询是原生MySql查询，而不是Jpql查询。

@Query("select ...", nativeQuery = true)
    List<Bean> loadGroupedCustomerPrepaidTransactions(...);

【讨论】：

【解决方案4】：

我认为 JPQL 没有 if - 所以你必须使用 CASE WHEN ... ELSE ...，就像这样：

SELECT e.name, CASE WHEN (e.salary >= 100000) THEN 1 WHEN (e.salary < 100000) THEN 2 ELSE 0 END from Employee e

【讨论】：