動態 JPA 標准生成器

Question

我正在使用 Spring 啟動 JPA 到下面執行下面的查詢

select DELTA_TYPE,OPERATION_ID,COUNT(*) from ACTIVE_DISCREPANCIES ad group by DELTA_TYPE,OPERATION_ID

DELTA_TYPE、OPERATION_ID 等可能來自外部系統，在存儲庫 class 中我嘗試執行本機查詢

    @Query(value="select OPERATION_ID,DELTA_TYPE,count(*) from ACTIVE_DISCREPANCIES ad group by ?1",nativeQuery = true)
    public List<Object[]> groupByQuery(@Param("reconType") String recGroupColumns);

其中 recGroupColumns="DELTA_TYPE,OPERATION_ID" 但沒有工作，因為@param 將拆分'，'

我的第二個選擇是標准查詢

public List<Object[]> getReconGroupList() {
        String recGroupColumns = "OPERATION_ID,DELTA_TYPE";
        String[] arrStr = recGroupColumns.split(",");
        CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
        CriteriaQuery<Object[]> query = criteriaBuilder.createQuery(Object[].class);
        Root<ActiveDiscrepancies> adr = query.from(ActiveDiscrepancies.class);
        query.groupBy(adr.get("operationId"), adr.get("deltaType"));

    // query.groupBy(adr.get("deltaType"));
    query.multiselect(adr.get("operationId"), adr.get("deltaType"), criteriaBuilder.count(adr));
    TypedQuery<Object[]> typedQuery = entityManager.createQuery(query);
    List<Object[]> resultList = typedQuery.getResultList();
    return resultList;
}

在這里如何動態傳遞 groupBy 和多選？

Answer 1

使用投影我們可以解決這種情況，下面是代碼

     Criteria criteria = getSession().createCriteria(ActiveDiscrepancies.class);

      ProjectionList projectionList = Projections.projectionList();

      for(String str : colList) {
        projectionList.add(Projections.groupProperty(str));
      }
        projectionList.add(Projections.rowCount());
        criteria.setProjection(projectionList);
        List results = criteria.list();

        getSession().close();