diff --git a/dao/class_dao.py b/dao/class_dao.py
new file mode 100644
index 0000000..1c90c18
--- /dev/null
+++ b/dao/class_dao.py
@@ -0,0 +1,118 @@
+from pymysql import IntegrityError
+from models.class_model import Class,Teacher
+from sqlalchemy.orm import Session
+def add_class_dao(c,db):
+    try:
+        head_teacher = db.query(Teacher).filter(Teacher.id == c['ht_id']).first()
+        if head_teacher is None:
+           return False, '指定的班主任不存在'
+        class_teacher = db.query(Teacher).filter(Teacher.id == c['t_id']).first()
+        if class_teacher is None:
+           return False, '指定的授课老师不存在'
+        if db.query(Class).filter(
+                Class.class_id == c['class_id'],#如果请求体传进来的classid在表里找的到
+                Class.is_deleted==0 #且没有处于软删除状态
+        ).first():
+            return False, '班级编号已存在'
+        new_class = Class(**c)
+        db.add(new_class)
+        db.commit()
+        return True,new_class
+    except Exception as e:
+        db.rollback()
+        print('创建失败：',repr(e))
+        return False,str(e)
+def update_class_dao(id,update_data,db):
+    try:
+        rows = db.query(Class).filter(Class.id == id).update(update_data)
+    except Exception as e:
+        db.rollback()
+        print('更新失败：', repr(e))
+        return False, str(e)
+    else:
+        db.commit()
+        return rows
+'''
+def get_class_dao(id,db,page,page_size):
+        q = db.query(Class)
+        if id:
+            q = q.filter(Class.id == id,Class.is_deleted==0)
+        rows = q.offset((page-1)*page_size ).limit(page_size).all()
+        if rows:
+            return[{'class_id':i.id,'class_no':i.class_no,'class_name':i.class_name,'ht_id':i.ht_id,'t_id':i.t_id,'start_time':i.start_time}for i in rows]
+'''
+def get_class_list_dao(db: Session, page: int, page_size: int, **filters):
+    #软删除过滤
+    q = db.query(Class).filter(Class.is_deleted == 0)
+
+    # 精确匹配字段
+    if filters.get("class_no"):
+        q = q.filter(Class.class_id == filters["class_id"])
+    if filters.get("ht_id") is not None:
+        q = q.filter(Class.ht_id == filters["ht_id"])
+    if filters.get("t_id") is not None:
+        q = q.filter(Class.t_id == filters["t_id"])
+
+    # 模糊匹配字段（例如班级名称）
+    if filters.get("class_name"):
+        q = q.filter(Class.class_name.like(f"%{filters['class_name']}%"))
+
+    # 获取满足条件的总记录数（分页必备）
+    total = q.count()
+
+    # 分页查询
+    rows = q.offset((page - 1) * page_size).limit(page_size).all()
+
+    items = [ #如果匹配不到，则会返回空列表
+        {
+            'id': i.id,
+            'class_id': i.class_id,
+            'class_name': i.class_name,
+            'ht_id': i.ht_id,
+            't_id': i.t_id,
+            'start_time': i.start_time
+        }
+        for i in rows
+    ]
+    return total, items
+def get_class_by_id_dao(id: int, db: Session):
+    i = db.query(Class).filter(Class.id == id, Class.is_deleted == 0).first()
+    if not i:
+        return None
+    return {
+        'id': i.id,
+        'class_id': i.class_id,
+        'class_name': i.class_name,
+        'ht_id': i.ht_id,
+        't_id': i.t_id,
+        'start_time': i.start_time
+    }
+def delete_class_dao(id,db): #软删除
+    try:
+        rows = (db.query(Class)
+                .filter(Class.id == id,Class.is_deleted==0)#只匹配还没处于软删除状态的行
+                .update({Class.is_deleted:1},synchronize_session=False))#软删除就是把这个字段改成True
+    except Exception as e:
+        db.rollback()
+        print('删除失败：', repr(e))
+        return False, str(e)
+    else:
+        db.commit()
+        return rows
+def hard_delete_class_dao(id,db): #物理删除
+    try:
+        rows = (db.query(Class).filter(Class.id == id).delete(synchronize_session=False))
+        db.commit()
+        return rows
+    except IntegrityError:
+        db.rollback()
+        return False, '该班级被其他数据引用，无法彻底删除'
+    except Exception as e:
+        db.rollback()
+        print('物理删除失败', repr(e))
+        return False, str(e)
+def class_no_exist(class_id,db):
+    return (db.query(Class)
+            .filter(Class.class_id == class_id,Class.is_deleted==0)
+            .first() is not None
+            )