关于JPA原生SQL查询

关于JPA写原生SQL一直很有争议,大部分说JPA不适合写SQL,或者对于SQL的支持很垃圾,但是在我使用JPA的过程中,发现JPA写SQL其实还可以,那么咱们就讨论下JPA原生SQL的写法.
关于JPA原生SQL是采用entityManager类进行查询,当前查询可以返回Map对象,当然也可以返回List对象.

定义原生接口

BaseDao.java

/**
 *  这里为了演示JPA原生sql,就先定义个空接口, 如果运用到项目中,这里可以定义 
 *  一些公共的查询方法,如简单的单表增删改查
 *  如: public T select(String id);
 *     public List selectT(String id);
 *      .....   
**/
  public interface BaseDao {

  }

BaseDaoIml.java

@Repository
public class BaseDaoImpl implements BaseDao {

    @PersistenceContext
    private EntityManager entityManager;
    private Class clz;

    public Class getClz() {
        if (clz == null) {
            // 获取泛型的Class对象
            clz = ((Class) (((ParameterizedType) (this.getClass().getGenericSuperclass())).getActualTypeArguments()[0]));
        }
        return clz;
    }

    public List listBySQL(String sql) {
        return null;
    }

    public Integer getCount(String sql, Map maps) {
        Query query = entityManager.createNativeQuery(sql);
        setAliasParameter(query, maps);
        BigInteger count = new BigInteger("0");
        try {
            count = (BigInteger) query.getSingleResult();
        } catch (NoResultException ex) {

        }


        return count.intValue();
    }


    public List executeObject(String queryStr) {
        Query query = entityManager.createNativeQuery(queryStr);
        List resultList = query.getResultList();
        return resultList;
    }


    public Page executeNativeQuery(String queryStr, QueryConditionVo queryConditionVo) {
        return executeNativeQuery(queryStr, queryConditionVo, null);
    }

    public T executeNativeQueryObject(String querySQL) {
        return executeNativeQueryObject(querySQL, null);
    }

    public List executeNativeQuery(String sql, Object... params) {
        Query query = entityManager.createNativeQuery(sql);
        setParameter(query, params);
        query.unwrap(SQLQuery.class).setResultTransformer(Transformers.aliasToBean(getClz()));
        List resultList = query.getResultList();
        return resultList;
    }


    public List executeNativeQuery(String sql, Map alias) {
        Query query = entityManager.createNativeQuery(sql);
        setAliasParameter(query, alias);
        query.unwrap(SQLQuery.class).setResultTransformer(Transformers.aliasToBean(getClz()));
        List resultList = query.getResultList();
        return resultList;
    }


    public T executeNativeQueryObject(String querySQL, Object... param) {
        Query query = entityManager.createNativeQuery(querySQL);
        query.unwrap(SQLQuery.class).setResultTransformer(Transformers.aliasToBean(getClz()));
        setParameter(query, param);
        return (T) query.getSingleResult();
    }

    public  Page executeNativeQuery(String queryStr, QueryConditionVo queryConditionVo, Map maps) {
        return executeNativeQuery(queryStr, queryConditionVo, maps, null);
    }


    public  Page executeNativeQuery(String queryStr, QueryConditionVo queryConditionVo, Map alias, Object... params) {
        String cq = getCountHql(queryStr);
        queryStr = initSort(queryStr, queryConditionVo);
        Query query = entityManager.createNativeQuery(queryStr);
        Query cquery = entityManager.createNativeQuery(cq);
        query.unwrap(SQLQuery.class).setResultTransformer(Transformers.aliasToBean(getClz()));
        setAliasParameter(query, alias);
        setAliasParameter(cquery, alias);
        setParameter(query, params);
        setParameter(cquery, params);
        BigInteger total = new BigInteger("0");
        try {
            total = (BigInteger) cquery.getSingleResult();
        } catch (NoResultException ex) {

        }
        int page = queryConditionVo.getPagination().getPage();
        int size = queryConditionVo.getPagination().getSize();
        query.setFirstResult(page * size);
        query.setMaxResults(size);
        List resultList = query.getResultList();
        Pageable pageable = new PageRequest(page, size);
        return new PageImpl(resultList, pageable, total.longValue());
    }

    private void setParameter(Query query, Object[] args) {
        if (args != null && args.length > 0) {
            int index = 1;
            for (Object arg : args) {
                if (arg == null) {
                    continue;
                }
                query.setParameter(index++, arg);
            }
        }
    }

    private void setAliasParameter(Query query, Map alias) {
        if (alias != null) {
            Set keys = alias.keySet();
            for (String key : keys) {
                Object val = alias.get(key);
                if (val instanceof Collection) {
                    // 查询条件是列表
                    query.setParameter(key, (Collection) val);
                } else {
                    query.setParameter(key, val);
                }
            }
        }
    }

    private String initSort(String hql, QueryConditionVo vo) {

        if (vo != null && null != vo.getSort() && vo.getSort().size() > 0) {
            Map map = vo.getSort();
            for (String key : map.keySet()) {
                hql += " order by " + key + " " + map.get(key);
            }
        }
        return hql;
    }

    protected String getCountHql(String hql) {
        String e = hql.substring(hql.toLowerCase().indexOf("from"));
        String c = "select ifnull(count(*),0) " + e;

        return c;
    }


    public Integer findBySql(String sql, Object... args) {
        Query query = entityManager.createNativeQuery(sql);
        int i = 0;
        for (Object arg : args) {
            query.setParameter(++i, arg);
        }
        return query.getResultList().size();
    }

    public Integer findBySql(String sql, Map args) {
        Query query = entityManager.createNativeQuery(sql);
        setAliasParameter(query, args);
        return query.getResultList().size();
    }
}

以上就是原生SQL的具体实现.关于调用,请看下面的例子

public interface IDataSourceCustomRepository extends BaseDao {


    Page findDataSourceByAdmin(QueryConditionVo queryConditionVo, User user);

    Page findDataSourceByGuest(QueryConditionVo queryConditionVo, User user);

}

 @Repository
public class DataSourceCustomRepository extends BaseDaoImpl implements IDataSourceCustomRepository {

    @Override
    public Page findDataSourceByAdmin(QueryConditionVo queryConditionVo, User user) {
        StringBuilder sql = new StringBuilder("SELECT T.* FROM ( SELECT " +
                "   mds.id,   " +
                "   DATE_FORMAT(mds.gmt_create,'%Y-%m-%d %H:%i:%s') AS gmtCreate,   " +
                "   mds.back_ground_color AS backGroundColor,   " +
                "   mds.data_list_name AS dataListName,   " +
                "   mds.data_list_path AS dataListPath,   " +
                "   mds.data_source_content AS dataSourceContent,   " +
                "   mds.data_source_name AS dataSourceName,   " +
                "   if(mds.data_source_state = 'PRIVATE','PUBLIC','PUBLIC')AS dataSourceState,  " +
                "   IF( 1, 'ADMIN' ,'ADMIN') AS userState," +
                "   mds.font_path AS fontPath,   " +
                "   mds.layers_num AS layersNum,   " +
                "   mds.map_thumbnail_name AS mapThumbnailName,   " +
                "   mds.map_thumbnail_path AS mapThumbnailPath,   " +
                "   mds.remark AS remark,   " +
                "   mds.province AS province,   " +
                "   mds.city AS city,   " +
                "   mds.area AS area,   " +
                "   mds.create_by_id AS createBy ," +
                "   mds.is_deleted AS isDeleted, " +
                "   mds.address AS address," +
                "  mds.resource_state AS resourceState," +
                "   (select COUNT(*) from m_project_datasource where mds.id=datasource_id) projectCount " +
                " FROM   " +
                "   m_data_source AS mds  ) AS T WHERE 1=1  and T.isDeleted='N' ");
        SearchDataSourceModel searchDataSourceModel = JSON.parseObject(queryConditionVo.getParams(), SearchDataSourceModel.class);
        Map map = Maps.newHashMap();
        return getDataSourceModels(queryConditionVo, searchDataSourceModel, sql, map);

    }

    @Transactional
    public Page findDataSourceByGuest(QueryConditionVo queryConditionVo, User user) {
        SearchDataSourceModel searchDataSourceModel = JSON.parseObject(queryConditionVo.getParams(), SearchDataSourceModel.class);
        StringBuilder sql = new StringBuilder("SELECT T.* FROM ( SELECT " +
                "  mds.id, " +
                "   DATE_FORMAT(mds.gmt_create,'%Y-%m-%d %H:%i:%s') AS gmtCreate,   " +
                "  mds.back_ground_color AS backGroundColor, " +
                "  mds.data_list_name AS dataListName, " +
                "  mds.data_list_path AS dataListPath, " +
                "  mds.data_source_content AS dataSourceContent, " +
                "  mds.data_source_name AS dataSourceName, " +
                "IF " +
                "  ( " +
                "    mdsp.application_enum IS NULL, " +
                "    mds.data_source_state, " +
                "    mdsp.application_enum  " +
                "  ) AS dataSourceState, " +
                "  mds.font_path AS fontPath, " +
                "  mds.layers_num AS layersNum, " +
                "  mds.map_thumbnail_name AS mapThumbnailName, " +
                "  mds.map_thumbnail_path AS mapThumbnailPath, " +
                "  mds.remark AS remark, " +
                "  mds.province AS province, " +
                "  mds.city AS city, " +
                "  mds.area AS area,   " +
                "  mds.create_by_id AS createBy ," +
                "  mds.is_deleted AS isDeleted, " +
                "  mds.address AS address," +
                "  mds.resource_state AS resourceState," +
                "   (select COUNT(*) from m_project_datasource where mds.id=datasource_id) projectCount " +
                " FROM " +
                "  m_data_source AS mds " +
                "  LEFT JOIN ( SELECT * FROM m_data_source_application WHERE application_user =:userId AND apply_current_enum='CURRENT_APPLY') AS mdsp ON mds.id = mdsp.data_source_id " +
                " WHERE mds.is_deleted = 'N'  ) AS T WHERE 1=1 and T.isDeleted='N'  ");

        Map map = Maps.newHashMap();
        map.put("userId", user.getId());
        return getDataSourceModels(queryConditionVo, searchDataSourceModel, sql, map);
    }

    private Page getDataSourceModels(QueryConditionVo queryConditionVo, SearchDataSourceModel searchDataSourceModel, StringBuilder sql, Map map) {
        if (StringUtils.isNotEmpty(searchDataSourceModel.getDataSourceName())) {
            sql.append(" and  T.dataSourceName LIKE :dataSourceName");
            map.put("dataSourceName", "%" + searchDataSourceModel.getDataSourceName() + "%");
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getGmtCreateStart())) {
            sql.append(" and DATE_FORMAT(T.gmtCreate,'%Y-%m-%d') >= :gmtCreate");
            map.put("gmtCreate", searchDataSourceModel.getGmtCreateStart());
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getGmtCreateEnd())) {
            sql.append(" and  DATE_FORMAT(T.gmtCreate,'%Y-%m-%d') <= :gmtCreate");
            map.put("gmtCreate", searchDataSourceModel.getGmtCreateEnd());
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getSourceState())) {
            sql.append(" and  T.dataSourceState IN(:dataSourceState)");
            map.put("dataSourceState", searchDataSourceModel.getSourceState());
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getProvince())) {
            sql.append(" and  T.province =:province");
            map.put("province", searchDataSourceModel.getProvince());
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getCity())) {
            sql.append(" and  T.city = :city");
            map.put("city", searchDataSourceModel.getCity());
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getArea())) {
            sql.append(" and  T.area = :area");
            map.put("area", searchDataSourceModel.getArea());
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getResourceState())) {
            sql.append(" and  T.resourceState = :resourceState");
            map.put("resourceState", searchDataSourceModel.getResourceState());
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getUseState()) && searchDataSourceModel.getUseState().equals(UseState.USE)) {
            sql.append(" and  T.projectCount > 0");
        }
        if (!ObjectUtils.isEmpty(searchDataSourceModel.getUseState()) && searchDataSourceModel.getUseState().equals(UseState.NOT_USE)) {
            sql.append(" and  T.projectCount = 0");
        }
        return super.executeNativeQuery(sql.toString(), queryConditionVo, map);
    }

}

返回的实体类对象

@Data
public class DataSourceModel {

    private String id;
    /**
     * 数据源名称
     */

    private String dataSourceName;

    /**
     * gis数据源内容,这个就是URL地址
     */
    private String dataSourceContent;
    /**
     * 备注信息，简介
     */
    private String remark;
    /**
     * 创建人
     */
    private String createBy;
    /**
     * 更新人
     @OneToOne private User updateBy;*/
    /**
     * 字体地址
     */
    private String fontPath;

    /**
     * 雪碧图地址
     */
    private String spritePath;
    /**
     * 数据源状态 private:私有
     * 
     * public : 公开
     */
    private String dataSourceState;

    /**
     * 数据清单，文件路径
     */
    private String dataListPath;

    /**
     * 地图缩略图，文件路径
     */
    private String mapThumbnailPath;

    /**
     * 数据清单，文件名称
     */
    private String dataListName;


    /**
     * 地图缩略图，图片名称 申请
     */
    private String mapThumbnailName;

    /**
     * 图层总数
     */
    private String layersNum;

    /**
     * 背景色，用户前端展示
     */
    private String backGroundColor;


    /**
     * 区域地址
     */
    private String province;


    private String city;


    private String area;

    private String gmtCreate;

    private String userState = UserState.GUEST.getName();


    private String isDeleted;

    private BigInteger projectCount;

    private String address;

    private String resourceState;

}

以上就是原生SQL返回实体类的调用方式,是不是很简单呢. 注意:JPA返回对象属性时,会有较高的要求,一般int类型时,jpa会返回biginteger,等等,有些属性需要注意,不过报错时,jpa会给出友好的提示,修改属性就好了

对了,关于BaseDaoImpl.java的QueryConditionVo类,这里没有给出,请翻阅我之前的文章JPA表达式(一)文章,里面有具体写法

欢迎小伙伴留言.

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