今天完成的事情：（一定要写非常细致的内容，比如说学会了盒子模型，了解了Margin）

model

package org.example.model;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
public class User {
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private Long pid;
    private Long level;
    private String name;
    private String state;
    private Long createAt;
    private Long updateAt;
    private String author;
    private Long sort;
    public User() {
    }

    public User(Long id, Long pid, Long level, String name, String state, Long createAt, Long updateAt, String author, Long sort) {
        this.id = id;            // 主键ID
        this.pid = pid;          // 父ID
        this.level = level;      // 层级
        this.name = name;        // 名称
        this.state = state;      // 状态
        this.createAt = createAt;    // 创建时间
        this.updateAt = updateAt;    // 更新时间
        this.author = author;    // 创建人
        this.sort = sort;        // 排序
    }
        public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public Long getPid() {
        return pid;
    }

    public void setPid(Long pid) {
        this.pid = pid;
    }

    public Long getLevel() {
        return level;
    }

    public void setLevel(Long level) {
        this.level = level;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public Long getCreateAt() {
        return createAt;
    }

    public void setCreateAt(Long createAt) {
        this.createAt = createAt;
    }

    public Long getUpdateAt() {
        return updateAt;
    }

    public void setUpdateAt(Long updateAt) {
        this.updateAt = updateAt;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public Long getSort() {
        return sort;
    }

    public void setSort(Long sort) {
        this.sort = sort;
    }
@Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", pid=" + pid +
                ", level=" + level +
                ", name='" + name + '\'' +
                ", state='" + state + '\'' +
                ", createAt=" + createAt +
                ", updateAt=" + updateAt +
                ", author='" + author + '\'' +
                ", sort=" + sort +
                '}';
    }
    }

UserMapper

package org.example.mapper;

import org.example.model.User;
import java.util.List;

public interface UserMapper {
    // 查询
    List<User> selectAll();
    User selectById(Long id);
    List<User> selectByPid(Long pid);

    // 新增
    int insert(User user);

    // 更新
    int update(User user);

    // 删除
    int deleteById(Long id);
}

明天计划的事情：（一定要写非常细致的内容）
遇到的问题：（遇到什么困难，怎么解决的）
收获：（通过今天的学习，学到了什么知识）