feat: 多班级版班级管理系统 v2.0

技术栈：Go (Gin + GORM) + PHP + MySQL 5.7 + Redis

主要功能：
- 多班级完全隔离（class_id 贯穿全系统）
- 后端 Go Gin（端口 56789），Nginx 反代
- 超级管理员独立登录（env 配置，默认账密 admin/Admin123）
- bcrypt 密码加密（无 PASSWORD_SALT）
- 科任老师/课代表新角色
- 课代表作业管理页面
- 排行榜分项排行（操行分/考勤/作业）
- 角色加减分上下限由班主任配置
- 家长改密功能（可开关）
- 班级角色按需开关
- 宿舍号格式：南0-000
- 周度/月度重置功能
- MySQL 5.7 兼容
- 43 轮代码审查 + 全部修复

开发者: Canglan
版权归属: Sea Network Technology Studio
许可证: Apache License 2.0

backend-go/internal/repository/class_repo.go

@@ -0,0 +1,184 @@
+// ===========================================
+// 多班级版班级管理系统 - Go 后端
+//
+// 开发者: Canglan
+// 联系方式: admin@sea-studio.top
+// 版权归属: Sea Network Technology Studio
+// 许可证: Apache License 2.0
+//
+// 版权所有 © Sea Network Technology Studio
+// ===========================================
+
+package repository
+
+import (
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+
+	"hz-gitea.sea-studio.top/canglan/SharedClassManager/internal/model"
+)
+
+// ClassRepo 班级数据访问层
+type ClassRepo struct {
+	db *gorm.DB
+}
+
+// NewClassRepo 创建班级 Repository
+func NewClassRepo(db *gorm.DB) *ClassRepo {
+	return &ClassRepo{db: db}
+}
+
+// GetDB 获取底层数据库连接
+func (r *ClassRepo) GetDB() *gorm.DB {
+	return r.db
+}
+
+// GetByID 根据ID获取班级信息
+func (r *ClassRepo) GetByID(classID int) (*model.Class, error) {
+	var class model.Class
+	if err := r.db.Where("class_id = ?", classID).First(&class).Error; err != nil {
+		return nil, err
+	}
+	return &class, nil
+}
+
+// GetAll 获取所有班级列表
+func (r *ClassRepo) GetAll(includeDisabled bool) ([]model.Class, error) {
+	var classes []model.Class
+	query := r.db.Where("1 = 1")
+	if !includeDisabled {
+		query = query.Where("status = 1")
+	}
+	if err := query.Order("class_id").Find(&classes).Error; err != nil {
+		return nil, err
+	}
+	return classes, nil
+}
+
+// GetByName 根据班级名称获取班级
+func (r *ClassRepo) GetByName(className string) (*model.Class, error) {
+	var class model.Class
+	if err := r.db.Where("class_name = ?", className).First(&class).Error; err != nil {
+		return nil, err
+	}
+	return &class, nil
+}
+
+// Create 创建班级
+func (r *ClassRepo) Create(class *model.Class) (int, error) {
+	if err := r.db.Create(class).Error; err != nil {
+		return 0, err
+	}
+	return class.ClassID, nil
+}
+
+// Update 更新班级信息（仅更新非零值字段）
+func (r *ClassRepo) Update(classID int, updates map[string]interface{}) error {
+	if len(updates) == 0 {
+		return nil
+	}
+	return r.db.Model(&model.Class{}).
+		Where("class_id = ?", classID).
+		Updates(updates).Error
+}
+
+// Delete 删除班级（硬删除，需先确认无学生）
+func (r *ClassRepo) Delete(classID int) error {
+	return r.db.Where("class_id = ?", classID).Delete(&model.Class{}).Error
+}
+
+// GetStudentCount 获取班级活跃学生数量
+func (r *ClassRepo) GetStudentCount(classID int) (int64, error) {
+	var count int64
+	if err := r.db.Model(&model.Student{}).
+		Where("class_id = ? AND status = 1", classID).
+		Count(&count).Error; err != nil {
+		return 0, err
+	}
+	return count, nil
+}
+
+// HasActiveStudents 检查班级是否有活跃学生
+func (r *ClassRepo) HasActiveStudents(classID int) (bool, error) {
+	count, err := r.GetStudentCount(classID)
+	if err != nil {
+		return false, err
+	}
+	return count > 0, nil
+}
+
+// ========== 班级设置操作 ==========
+
+// GetSettings 获取班级的所有设置
+func (r *ClassRepo) GetSettings(classID int) ([]model.ClassSetting, error) {
+	var settings []model.ClassSetting
+	if err := r.db.Where("class_id = ?", classID).Find(&settings).Error; err != nil {
+		return nil, err
+	}
+	return settings, nil
+}
+
+// GetSetting 获取班级单个设置项
+func (r *ClassRepo) GetSetting(classID int, key string) (*model.ClassSetting, error) {
+	var setting model.ClassSetting
+	if err := r.db.Where("class_id = ? AND setting_key = ?", classID, key).First(&setting).Error; err != nil {
+		return nil, err
+	}
+	return &setting, nil
+}
+
+// SaveSetting 保存班级设置项（upsert）
+func (r *ClassRepo) SaveSetting(classID int, key, value string) error {
+	setting := model.ClassSetting{
+		ClassID:     classID,
+		SettingKey:  key,
+		SettingValue: value,
+	}
+	return r.db.Clauses(clause.OnConflict{
+		Columns:   []clause.Column{{Name: "class_id"}, {Name: "setting_key"}},
+		DoUpdates: clause.AssignmentColumns([]string{"setting_value"}),
+	}).Create(&setting).Error
+}
+
+// BatchSaveSettings 批量保存班级设置项
+func (r *ClassRepo) BatchSaveSettings(classID int, settings map[string]string) error {
+	for key, value := range settings {
+		if err := r.SaveSetting(classID, key, value); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ========== 班级功能开关操作 ==========
+
+// GetFeatures 获取班级的所有功能开关
+func (r *ClassRepo) GetFeatures(classID int) ([]model.ClassFeature, error) {
+	var features []model.ClassFeature
+	if err := r.db.Where("class_id = ?", classID).Find(&features).Error; err != nil {
+		return nil, err
+	}
+	return features, nil
+}
+
+// GetFeature 获取班级单个功能开关
+func (r *ClassRepo) GetFeature(classID int, featureKey string) (*model.ClassFeature, error) {
+	var feature model.ClassFeature
+	if err := r.db.Where("class_id = ? AND feature_key = ?", classID, featureKey).First(&feature).Error; err != nil {
+		return nil, err
+	}
+	return &feature, nil
+}
+
+// SaveFeature 保存班级功能开关（upsert）
+func (r *ClassRepo) SaveFeature(classID int, featureKey string, enabled int8) error {
+	feature := model.ClassFeature{
+		ClassID:    classID,
+		FeatureKey: featureKey,
+		Enabled:    enabled,
+	}
+	return r.db.Clauses(clause.OnConflict{
+		Columns:   []clause.Column{{Name: "class_id"}, {Name: "feature_key"}},
+		DoUpdates: clause.AssignmentColumns([]string{"enabled"}),
+	}).Create(&feature).Error
+}