hibernate - JPA/JPQL : AS identifier disallowed in SELECT clause

Question

我有一个非常复杂的 JPQL 查询表单

  SELECT NEW com.domain.project.view.StandingsStatLine(
      ro.id                                                                                                 AS rid
    , cl.name                                                                                               AS team
    , te.ordinalNbr + 1                                                                                     AS nr
    , pa.wasWithdrawn                                                                                       AS wd

    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1 ELSE 0 END)                                           AS g
    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore > sca.finalScore THEN 1 ELSE 0 END)                                      AS w
    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore < sca.finalScore THEN 1 ELSE 0 END)                                      AS l
    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore = 20 AND sca.finalScore =  0 THEN 1 ELSE 0 END)                          AS wbr
    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore =  0 AND sca.finalScore = 20 THEN 1 ELSE 0 END)                          AS lbr
    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore =  0 AND sca.finalScore =  0 THEN 1 ELSE 0 END)                          AS blbr

    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore > sca.finalScore THEN 1 ELSE 0 END)
      + SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1 ELSE 0 END)
      - SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore = 0 AND sca.finalScore = 20 THEN 1 ELSE 0 END)                         AS rp
    , CASE WHEN (  SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore > sca.finalScore THEN 1 ELSE 0 END)
                 + SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1 ELSE 0 END)
                 - SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore = 0 AND sca.finalScore = 20 THEN 1 ELSE 0 END)
                 - SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1 ELSE 0 END))
                   / SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1.0 ELSE 0.0 END) >= 0.0
           THEN ((  SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore > sca.finalScore THEN 1 ELSE 0 END)
                 + SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1 ELSE 0 END)
                 - SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore = 0 AND sca.finalScore = 20 THEN 1 ELSE 0 END)
                 - SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1 ELSE 0 END))
                   / SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1.0 ELSE 0.0 END))
           ELSE 0.0 END                                                                                                                                               AS nrp
    , CASE WHEN SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1 ELSE 0 END) > 0
           THEN  (SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore > sca.finalScore THEN 1.0 ELSE 0.0 END)
                / SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN 1 ELSE 0 END))
           ELSE NULL END                                                                                                                                              AS wperc

    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore IS NOT NULL THEN scf.finalScore ELSE 0 END)                              AS ptsf
    , SUM(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND sca.finalScore IS NOT NULL THEN sca.finalScore ELSE 0 END)                              AS ptsa

    , MAX(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore NOT IN (0, 20) THEN scf.finalScore ELSE NULL END)                        AS hi
    , MAX(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore NOT IN (0, 20) THEN scf.game.id ELSE NULL END)                           AS higid
    , MIN(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore NOT IN (0, 20) THEN scf.finalScore ELSE NULL END)                        AS lo
    , MIN(CASE WHEN paf.wasWithdrawn = FALSE AND paa.wasWithdrawn = FALSE AND scf.finalScore NOT IN (0, 20) THEN scf.game.id ELSE NULL END)                           AS logid
    )
  FROM Club cl
    JOIN cl.teams te
    JOIN te.rosters ro
    JOIN ro.season se
    JOIN ro.participations pa
    JOIN pa.group gr
    JOIN gr.round rd
    JOIN rd.subCompetition sc
    JOIN sc.competition cn
    JOIN gr.games ga
    JOIN ga.scores scf
    JOIN ga.scores sca
    JOIN scf.roster rof
    JOIN sca.roster roa
    JOIN rof.participations paf
    JOIN roa.participations paa
  WHERE ...
  GROUP BY ...
  ORDER BY pa.wasWithdrawn, nrp DESC, w DESC, lbr, g DESC, cl.shorthand

使用 Hibernate 4.x 运行它没有问题，但是 Eclipse Dali 在构造函数表达式的几乎每一行上都显示 JPQL 错误。删除 ... AS <identifier>摆脱这些错误。

我查看了 JPQL BNF http://en.wikibooks.org/wiki/Java_Persistence/JPQL_BNF在这里，但我找不到 AS在 SELECT 子句层次结构中。

问题:

这是 Hibernate 特定的语法吗？

为什么 JPQL 不支持这个？

有时表达式会变得非常复杂，我想通过 AS 记录表达式的实际含义。子句，特别是考虑到 JPQL 没有注释功能。这是 JPQL 恕我直言的真正缺陷。

此外，Hibernate 允许我引用这些 AS es 在 ORDER BY子句，它允许我重用上面的复杂语句。

也许我的表达方式可以缩短，但在其他情况/项目中，复杂性仍然很高。

谢谢

Answer 1

找到了。

根据位于 http://en.wikibooks.org/wiki/Java_Persistence/JPQL_BNF#New_in_JPA_2.0 的 JPQL BNF JPA 2.0 应该支持这一点。请注意，倒数第二个示例。

这几乎回答了为什么 Eclipse Dali 显示 JPQL 验证错误的原始问题。看来是大理的问题。