<insert id="insert">
    insert into admin (username, password, name, avatar, role)
    values (#{username}, #{password}, #{name}, #{avatar}, #{role})
</insert>

delete from admin where id = #{id}

<update id="updateById">
    update admin
    <set>
        <if test="username != null"> username = #{username}, </if>
        <if test="password != null"> password = #{password}, </if>
        <if test="name != null"> name = #{name}, </if>
        <if test="avatar != null"> avatar = #{avatar}, </if>
        <if test="role != null"> role = #{role} </if>
    </set>
    where id = #{id}
</update>

/**
 * 查询单个
 */
@GetMapping("/selectById/{id}")
public Result selectById(@PathVariable Integer id) {
    Admin admin = adminService.selectById(id);
    return Result.success(admin);
}

@GetMapping("/selectAll")
public Result selectAll() {
    List<Admin> list = adminService.selectAll();
    return Result.success(list);
}

/**
 * 查询所有
 */
@GetMapping("/selectPage")
public Result selectPage(@RequestParam(defaultValue = "1") Integer pageNum, @RequestParam(defaultValue = "10") Integer pageSize) {
    PageInfo pageInfo = adminService.selectPage(pageNum, pageSize);
    return Result.success(pageInfo);
}

public PageInfo selectPage(Integer pageNum, Integer pageSize) {
    PageHelper.startPage(pageNum, pageSize);
    List<Admin> list = this.selectAll();
    return PageInfo.of(list);
}