删除：未使用代码

src/dao/BaseDAO.java

@@ -21,13 +21,6 @@ public interface BaseDAO<T> {
      */
     int deleteById(int id);
 
-    /**
-     * 更新记录
-     * @param entity 实体对象
-     * @return 影响的行数
-     */
-    int update(T entity);
-
     /**
      * 根据ID查询记录
      * @param id 主键ID

src/dao/impl/LeaveRequestDAOImpl.java

@@ -87,46 +87,6 @@ public class LeaveRequestDAOImpl implements LeaveRequestDAO {
         }
     }
 
-    /**
-     * 更新请假申请信息
-     * 根据请假申请对象的ID更新其他字段的值
-     * 
-     * @param request 包含更新信息的请假申请对象
-     * @return 影响的行数，更新成功返回1，失败返回0
-     */
-    @Override
-    public int update(LeaveRequest request) {
-        if (request == null || request.getStudent() == null) {
-            return 0;
-        }
-        
-        String sql = "UPDATE leave_requests SET student_id = ?, start_time = ?, " +
-                    "end_time = ?, status = ?, duration = ?, location = ?, " +
-                    "reason_type = ?, reason_detail = ?, is_leaving_city = ?, " +
-                    "request_time = ? WHERE id = ?";
-        try (Connection conn = DatabaseUtil.getConnection();
-             PreparedStatement stmt = conn.prepareStatement(sql)) {
-            
-            // 设置预处理语句的参数
-            stmt.setInt(1, request.getStudent().getId());
-            stmt.setTimestamp(2, new Timestamp(request.getStartTime().getTime()));
-            stmt.setTimestamp(3, new Timestamp(request.getEndTime().getTime()));
-            stmt.setString(4, request.getStatus().name());
-            stmt.setDouble(5, request.getDuration());
-            stmt.setString(6, request.getLocation());
-            stmt.setString(7, request.getReasonType());
-            stmt.setString(8, request.getReasonDetail());
-            stmt.setBoolean(9, request.isLeavingCity());
-            stmt.setTimestamp(10, new Timestamp(request.getRequestTime().getTime()));
-            stmt.setInt(11, request.getId());
-            
-            return stmt.executeUpdate();
-        } catch (SQLException e) {
-            e.printStackTrace();
-            return 0;
-        }
-    }
-
     /**
      * 根据ID查询请假申请信息
      * 同时会关联查询学生信息

src/dao/impl/TeacherDAOImpl.java

@@ -73,34 +73,6 @@ public class TeacherDAOImpl implements TeacherDAO {
         }
     }
 
-    /**
-     * 更新教师信息
-     * 根据教师对象的ID更新其他字段的值
-     * 
-     * @param teacher 包含更新信息的教师对象
-     * @return 影响的行数，更新成功返回1，失败返回0
-     */
-    @Override
-    public int update(Teacher teacher) {
-        String sql = "UPDATE teachers SET teacher_id = ?, name = ?, department = ?, contact = ?, password = ? WHERE id = ?";
-        try (Connection conn = DatabaseUtil.getConnection();
-             PreparedStatement stmt = conn.prepareStatement(sql)) {
-            
-            // 设置预处理语句的参数
-            stmt.setString(1, teacher.getTeacherId());
-            stmt.setString(2, teacher.getName());
-            stmt.setString(3, teacher.getDepartment());
-            stmt.setString(4, teacher.getContact());
-            stmt.setString(5, teacher.getPassword());
-            stmt.setInt(6, teacher.getId());
-            
-            return stmt.executeUpdate();
-        } catch (SQLException e) {
-            e.printStackTrace();
-            return 0;
-        }
-    }
-
     /**
      * 根据ID查询教师信息
      *