具有子查询的 JPA 规范存在失败 SQL Server 语法

Question

给定 2 个表，设计状态（通过复合键定义唯一状态）和状态组（定义从设计状态到用户组的外部参照记录），我正在尝试实现一个规范，该规范返回给定用户组的设计状态记录。设计状态与状态组是一对多的关系。下面的代码通过 H2 的单元测试产生正确的结果，但在运行时 SQL Server 中失败，','附近的语法不正确。 我追踪到以下select (costatusgr1_.DESIGN_STAT_CD, costatusgr1_.PRODUCT_ID, costatusgr1_.USER_GROUP_ID)。

如果这个子句是select * from CO_STATUS_GROUP costatusgr1_，SQL Server 将返回正确的结果。我正在寻求帮助修复我的规范以使用 EXISTS 或 IN 对子查询执行选择。

DDL如下：

create table CO_DES_STATUS
(
    PRODUCT_ID int not null,
    DESIGN_STAT_CD char(2) not null,
    DESIGN_STAT_DESC varchar(30),
    constraint PK_DES_STATUS
        primary key (PRODUCT_ID, DESIGN_STAT_CD)
)
create table CO_STATUS_GROUP
(
    PRODUCT_ID int not null,
    DESIGN_STAT_CD char(2) not null,
    USER_GROUP_ID varchar(8) not null,
    constraint PK_STATUS_GROUP
        primary key (PRODUCT_ID, DESIGN_STAT_CD, USER_GROUP_ID)
)

等效SQL如下：

select ds.* from CO_DES_STATUS ds 
    inner join CO_STATUS_GROUP sg on ds.PRODUCT_ID=sg.PRODUCT_ID and ds.DESIGN_STAT_CD=sg.DESIGN_STAT_CD
where ds.PRODUCT_ID=123 and sg.USER_GROUP_ID='group1'
order by ds.DESIGN_STAT_SEQ_NUM

对每个表和复合键使用实体，CoDesStatus 将一对多链接到 productId 和 designStatCd 上的 CoStatusGroup。

Predicate 方法的规范：

  public Predicate toPredicate(Root<CoDesStatus> root, CriteriaQuery<?> cq,
      CriteriaBuilder criteriaBuilder) {
    Subquery<CoStatusGroup> subquery = cq.subquery(CoStatusGroup.class);
    Root<CoStatusGroup> subqueryFrom = subquery.from(CoStatusGroup.class);
    Join<CoStatusGroup, CoDesStatus> subqueryJoin = subqueryFrom.join(CoStatusGroup_.coDesStatus);
    Predicate isAccessingUserPredicate = criteriaBuilder
        .equal(subqueryFrom.get(CoStatusGroup_.coSecurityUserGroup), this.accessingUserGroup);
    Predicate isProductPredicate = criteriaBuilder.equal(root.get(CoDesStatus_.id).get(CoDesStatusPK_.productId), coProd.getProductId());
    Predicate isParentEntityPredicate = criteriaBuilder
        .equal(subqueryJoin.get(CoDesStatus_.id), root.get(CoDesStatus_.id));
    subquery.select(subqueryFrom).where(isAccessingUserPredicate, isProductPredicate, isParentEntityPredicate);
    return criteriaBuilder.exists(subquery);
  }

Hibernate 查询结果：

Hibernate: select codesstatu0_.DESIGN_STAT_CD as DESIGN_S1_70_, codesstatu0_.PRODUCT_ID as PRODUCT_2_70_, codesstatu0_.DESIGN_STAT_DESC as DESIGN_S5_70_ from CO_DES_STATUS codesstatu0_ where exists (select (costatusgr1_.DESIGN_STAT_CD, costatusgr1_.PRODUCT_ID, costatusgr1_.USER_GROUP_ID) from CO_STATUS_GROUP costatusgr1_ inner join CO_DES_STATUS codesstatu2_ on costatusgr1_.DESIGN_STAT_CD=codesstatu2_.DESIGN_STAT_CD and costatusgr1_.PRODUCT_ID=codesstatu2_.PRODUCT_ID where costatusgr1_.USER_GROUP_ID='group1' and codesstatu0_.PRODUCT_ID=123 and codesstatu2_.DESIGN_STAT_CD=codesstatu0_.DESIGN_STAT_CD and codesstatu2_.PRODUCT_ID=codesstatu0_.PRODUCT_ID)

错误：

WARN  org.hibernate.engine.jdbc.spi.SqlExceptionHelper - SQL Error: 102, SQLState: S0001
ERROR org.hibernate.engine.jdbc.spi.SqlExceptionHelper - Incorrect syntax near ','.

Answer 1

在存在子查询中，最好还是选择一个常量，所以只需使用以下内容：

  public Predicate toPredicate(Root<CoDesStatus> root, CriteriaQuery<?> cq,
      CriteriaBuilder criteriaBuilder) {
    Subquery<Integer> subquery = cq.subquery(Integer.class);
    Root<CoStatusGroup> subqueryFrom = subquery.from(CoStatusGroup.class);
    Join<CoStatusGroup, CoDesStatus> subqueryJoin = subqueryFrom.join(CoStatusGroup_.coDesStatus);
    Predicate isAccessingUserPredicate = criteriaBuilder
        .equal(subqueryFrom.get(CoStatusGroup_.coSecurityUserGroup), this.accessingUserGroup);
    Predicate isProductPredicate = criteriaBuilder.equal(root.get(CoDesStatus_.id).get(CoDesStatusPK_.productId), coProd.getProductId());
    Predicate isParentEntityPredicate = criteriaBuilder
        .equal(subqueryJoin.get(CoDesStatus_.id), root.get(CoDesStatus_.id));
    subquery.select(criteriaBuilder.literal(1)).where(isAccessingUserPredicate, isProductPredicate, isParentEntityPredicate);
    return criteriaBuilder.exists(subquery);
  }