SpringBoot整合Mybatis注解版---update时出现的问题
问题描述：
1、sql建表语句
DROP TABLE IF EXISTS `department`;
CREATE TABLE `department` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`departmentName` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
2、Repository层使用注解方式，
语句如下：
@Update("UPDATE department SET departmentName=#{department.departmentName} WHERE id = #{id}")
public Integer updateEmp(Integer id, Department department);
显示错误信息：
org.apache.ibatis.binding.BindingException: Parameter 'department' not found. Available parameters are [arg1, arg0, param1, param2]
由错误信息得知，参数发现不了，或者解析不了，可以用 arg1, arg0, param1, param2替换，假如我们不是用POJO对象Department进行传参，
而是使用单个字段分别进行传值，那么结果。
@Update("UPDATE department SET departmentName=#{param2} WHERE id = #{param1}")
public Integer updateEmp( Integer id, String departmentName);
但是随着字段增多，我们使用POJO对象Department进行传参，需要在传过来的参数上添加注解，起别名的方式，获得参数，sql语句中通过对象名.属性名方式
获得参数的值，结果也是成功。
更改后得语句：
controller:
@PostMapping("/dept/{id}")
public Integer updateEmp(@PathVariable("id") Integer id,@Param("departmentName") Department department) {
return departmentService.updateEmp(id,departmentName);
}
-------------------------
service:
public Integer updateEmp(Integer id,Department department) {
Department dep = new Department(id,department);
return departmentMapper.updateEmp(id,dep);
}
-------------------------
repository:
@Mapper
public interface DepartmentMapper {
@Update("UPDATE department SET departmentName=#{department.departmentName} WHERE id = #{id}")
public Integer updateEmp(@Param("id") Integer id,@Param("department") Department department);
}