org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: org.apache.ibatis.reflection.ReflectionException: Error instantiating class cn.ddf.bean.Student with invalid types () or values ().
### Error querying database. Cause: org.apache.ibatis.reflection.ReflectionException: Error instantiating class cn.ddf.bean.Student with invalid types () or values ().
Cause: java.lang.NoSuchMethodException: cn.ddf.bean.Student.<init>()
### The error may exist in mapper/studentMapper.xml
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: select id,age,NAME from student
### Cause: org.apache.ibatis.reflection.ReflectionException: Error instantiating class cn.ddf.bean.Student with invalid types () or values ().
### The error may exist in mapper/studentMapper.xml
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: select id,age,NAME from student
### Cause: org.apache.ibatis.reflection.ReflectionException: Error instantiating class cn.ddf.bean.Student with invalid types () or values ().
Cause: java.lang.NoSuchMethodException: cn.ddf.bean.Student.<init>()
![](https://images2017.cnblogs.com/blog/1092953/201709/1092953-20170915163007891-640071755.png)
增删改没错,查询出错!
这是实体类中写了带参构造却没写无参构造方法!!