"""
使用ORM操作MySQL数据库，实现自定义的分页器
"""

class MyPaginator(object):

    def __init__(self, stmt, session, page_size=10):
        """
        :param stmt: 构造的查询对象
        :param session: 使用session来操作数据库
        :param page_size: 每一页数据量的大小，默认为10
        """
        self.stmt = stmt
        self.session = session
        self.page_size = page_size

    @property
    def data_count(self):
        """ 总记录数 """
        # 代码提示
        # select(count()).select_from(stmt)
        return 0

    @property
    def page_count(self):
        """ 总页数 """
        return 0

    def page(self, page=1):
        """
        查询当前页的数据
        :param page: 当前页码
        :return: list[dict])
        """
        return []


def main():
    """ 测试代码 """
    from sqlalchemy import select
    from sqlalchemy.orm import Session
    from school_models import Student
    from db_engine import engine_future as engine

    with Session(bind=engine, future=True) as session:
        stmt = select(Student)
        paginator = MyPaginator(stmt=stmt, session=session, page_size=16)
        print('总记录数：', paginator.data_count)
        print('总页数：', paginator.page_count)
        page = 3
        print(f'第{page}页数据为：')
        page_data = paginator.page(page=page)
        for item in page_data:
            print(item)


if __name__ == '__main__':
    main()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58