Hql substring length，hqlsubstring

Hql substring length，hqlsubstring

	public List<RoadBasicInfo> findByOfficialGrade(String officialGrade) {
		String hql = "select distinct new com.pengtu.entity.gl.RoadBasicInfo(roadName , substring(roadCode,0,length(roadCode)-6)) from RoadBasicInfo where officialGrade = '" + officialGrade + "'"; 
		return this.find(hql);
	}