方法一：使用Mybatis plus自带的insert()方法

entity

java">@Data
@AllArgsConstructor
@NoArgsConstructor
@TableName("student")
public class Student{@ApiModelProperty("主键")@TableId(type = IdType.AUTO)private Integer id;@ApiModelProperty("姓名")@TableField("name")private String name;
}

Mapper

java">@Mapper
public interface StudentMapper extends BaseMapper<Student> {
}

service

java">@Service
public class StudentService {
//引入mapper文件
@Autowired
private StudentMapper studentMapper;
//调用Mybatis自带的insert方法
studentMapper.insert(student);
//获取主键值
Integer id = student.getId();
}

方法二：自定义insert()方法

mapper

java">int insertStduent(Stduent stduent);

xml，注：一定要标注上这几个值，开启主键映射，否则会获取不到生成的主键值

useGeneratedKeys="true" keyProperty="id" keyColumn="id"

<insert id="insertStudent" parameterType="com.entity.Student" useGeneratedKeys="true" keyProperty="id" keyColumn="id">insert into student<trim prefix="(" suffix=")" suffixOverrides=","><if test="name != null and name != ''">name</if></trim><trim prefix="values(" suffix=")" suffixOverrides=","><if test="name != null and name != ''">#{name}</if></trim>
</insert>

service同上