错误原因:
数据库字段与实体类属性名称不一致
解决方法
使用as或使用resultmap
例如使用as
select b.id_ as id ,b.title_ as title ,b.bill_time_ as billTime,b.type_id_ as typeId,b.price_ as price ,b.explain_ as 'explain' ,bt.name_ as name from bill_ b left join bill_type_ bt on b.type_id_ =bt.id_