Jpa框架下拼接原生sql 并执行

利用jpa的entityManager 执行sql 并执行
其中：
EntityManager.createNativeQuery(SQL)返回的是Object对象
entityManager.createNativeQuery(SQL,WebInfo.class)返回的是映射后的实例对象

Query.getSingleResult() 执行SQL语句，返回一个查询结果，常用的还有以下方法
Query.getResultList() () 执行SQL语句，返回一个List集合
Query.getFirstResult() () 执行SQL语句，返回一个系列结果集合的第一个

直接上例子：

1. EntityManager.createNativeQuery(SQL)返回的是Object对象
   entityManager.createNativeQuery(SQL,WebInfo.class)返回的是映射后的实例对象

  public List<User> getByCompanyFinanceRoleManager(Long companyID , String authorityName){
        StringBuffer querySql = new StringBuffer("select a.* from art_user a , art_user_authority b where a.id = b.user_id and a.company_id = :companyId " +
                " and b.authority_name =  :authorityName");
        Query query = entityManager.createNativeQuery(querySql.toString() , User.class);
        query.setParameter("companyId" , companyID);
        query.setParameter("authorityName" , authorityName);
        List<User> list = query.getResultList();
        return list;
    }

2. Query.getSingleResult() 执行SQL语句，返回一个查询结果

  public Long getByFinanceRoleApplicationCount(ApplicationSearchParamDTO param){
        StringBuffer queryCount = new StringBuffer("select count(er.id) from atl_application er , atl_loan_application b where er.application_oid = b.application_oid and er.status not in (1010 ,1011)");
        getSql(queryCount , param);
        Query count = entityManager.createNativeQuery(queryCount.toString() );
        setQueryParam(count , param);
        Object obj = count.getSingleResult();
        Long countNum = ((BigInteger) obj).longValue();
        return countNum;
    }

public void getSql(StringBuffer querySql , ApplicationSearchParamDTO param ){
        //公司oid
        if (!StringUtils.isEmpty(param.getCompanyOID())) {
            querySql.append(" and er.company_oid = :companyOID ");
        }
        //申请人oid
        if (CollectionUtils.isNotEmpty(param.getApplicantOIDs())){
            querySql.append(" and er.applicant_oid in ( :applicantOID ) ");
        }
        if (!StringUtils.isEmpty(param.getBusinessCode())){
            querySql.append(" and b.business_code like CONCAT('%' , :businessCode , '%') ");
        }
        if (CollectionUtils.isNotEmpty(param.getDepartmentOIDs()) && CollectionUtils.isNotEmpty(param.getFinanceRoleCorporationOids()) && CollectionUtils.isEmpty(param.getCorporationOIDs())) {
            querySql.append(" and ( b.department_oid in ( :departmentOID ) or er.corporation_oid in ( :corporationOID ) OR b.department_oid is null OR er.corporation_oid is null )");
        }else if(CollectionUtils.isNotEmpty(param.getDepartmentOIDs()) && CollectionUtils.isEmpty(param.getCorporationOIDs())){
            querySql.append(" and ( b.department_oid in ( :departmentOID ) OR b.department_oid is null ) ");
        }else if(CollectionUtils.isNotEmpty(param.getFinanceRoleCorporationOids()) && CollectionUtils.isEmpty(param.getCorporationOIDs())){
            querySql.append(" and ( er.corporation_oid in ( :corporationOID ) OR er.corporation_oid is null ) ");
        }
        if (CollectionUtils.isNotEmpty(param.getCorporationOIDs())){
            querySql.append(" and er.corporation_oid in ( :corporationOID ) ");
        }
        //开始时间
        if (param.getStartDate() != null) {
            querySql.append(" and er.last_modified_date >= :startDate ");
        }
        //结束时间
        if (param.getEndDate() != null) {
            querySql.append(" and er.last_modified_date <= :endDate ");
        }
        //单据类型
        if (CollectionUtils.isNotEmpty(param.getType())) {
            querySql.append(" and er.type in ( :type ) ");
        }
        //单据状态
        if (CollectionUtils.isNotEmpty(param.getStatus())) {
            querySql.append(" and er.status in ( :status )");
        }
       /* //申请单oid
        if (CollectionUtils.isNotEmpty(param.getApplicationOIDs())) {
            querySql.append(" and er.application_oid in ( :applicationOID )");
        }*/

        //反选
        if(CollectionUtils.isNotEmpty(param.getExcludedApplicationOIDs())){
            querySql.append(" and er.application_oid not in ( :excludedApplicationOID )");
        }
    }

3. Query.getResultList()

    public List<DepartmentDTO> getDepartmentsOfReportLine(UUID reportLineOID) {
        String sql = "SELECT d.department_oid, d.`name` FROM art_department d INNER JOIN art_report_obj ro on ro.obj_oid = d.department_oid AND ro.obj_type = '2' "
            + "and ro.report_line_oid = '" + reportLineOID + "'";
        Query query = entityManager.createNativeQuery(sql);
        List<DepartmentDTO> list = new ArrayList<>();
        List<Object[]> rtList = query.getResultList();
        for (Object[] objects : rtList) {
            DepartmentDTO departmentDTO = new DepartmentDTO();
            departmentDTO.setDepartmentOID(UUID.fromString(objects[0].toString()));
            departmentDTO.setName(objects[1].toString());
            list.add(departmentDTO);
        }
        return list;
    }
    ```

直接参考例子，拼接正确sql 即可。


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