解决用户表映射问题以匹配实际数据库结构

之前，用户表列名在MyBatis映射中被错误地标注为`userId`和`group`，而数据库中的实际列名为`user_id`和`group`（无反引号）。此次更改通过在MyBatis注释中使用正确的列名来解决了该问题，确保了数据操作的正确执行。此外，还修正了选择语句中的列名，以确保查询能够正确执行并返回期望的结果。

src/main/java/top/suyiiyii/sims/mapper/UserMapper.java

@@ -21,7 +21,7 @@ public interface UserMapper extends BaseMapper<User> {
      * @param user 新用户对象
      * @return 影响的行数
      */
-    @Insert("insert INTO user (id,userId, username, password, name, email, group) VALUES (#{id},#{userId}, #{username}, #{password}, #{name}, #{email}, #{group})")
+    @Insert("insert INTO user (id,user_id, username, password, name, email, `group`) VALUES (#{id},#{userId}, #{username}, #{password}, #{name}, #{email}, #{group})")
     int addUser(User user);
 
     /**
@@ -38,12 +38,12 @@ public interface UserMapper extends BaseMapper<User> {
      * @return 影响的行数
      */
     @Update("UPDATE user SET " +
-            "userId = #{userId}, " +
+            "user_id = #{userId}, " +
             "username = #{username}, " +
             "password = #{password}, " +
             "name = #{name}, " +
             "email = #{email}, " +
-            "group = #{group} " +
+            "`group` = #{group} " +
             "WHERE id = #{id}")
     int updateUser(User user);
 
@@ -52,14 +52,14 @@ public interface UserMapper extends BaseMapper<User> {
      * @param userId 用户ID
      * @return 用户对象
      */
-    @Select("SELECT (id, userId, username, password, name, email, group) from user WHERE userId = #{userId}")
+    @Select("SELECT id, user_id, username, password, name, email, `group` from user WHERE user_id = #{userId}")
     User selectByUserId(Integer userId);
 
     /**
      * 查询所有用户信息
      * @return 用户列表
      */
-    @Select("SELECT id, userId, username, password, name, email, group FROM user")
+    @Select("SELECT id, user_id, username, password, name, email, `group` FROM user")
     List<User> selectAll();
 
   @Select("select * from user where username = #{username}")