初始提交

shierfeng-fastapi-backend/utils/page_util.py

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+import math
+from typing import Any
+
+from sqlalchemy import Row, Select, func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from common.vo import PageModel
+from utils.common_util import CamelCaseUtil
+
+
+class PageUtil:
+    """
+    分页工具类
+    """
+
+    @classmethod
+    def get_page_obj(cls, data_list: list, page_num: int, page_size: int) -> PageModel:
+        """
+        输入数据列表data_list和分页信息，返回分页数据列表结果
+
+        :param data_list: 原始数据列表
+        :param page_num: 当前页码
+        :param page_size: 当前页面数据量
+        :return: 分页数据对象
+        """
+        # 计算起始索引和结束索引
+        start = (page_num - 1) * page_size
+        end = page_num * page_size
+
+        # 根据计算得到的起始索引和结束索引对数据列表进行切片
+        paginated_data = data_list[start:end]
+        has_next = math.ceil(len(data_list) / page_size) > page_num
+
+        result = PageModel[Any](
+            rows=paginated_data, pageNum=page_num, pageSize=page_size, total=len(data_list), hasNext=has_next
+        )
+
+        return result
+
+    @classmethod
+    async def paginate(
+        cls, db: AsyncSession, query: Select, page_num: int, page_size: int, is_page: bool = False
+    ) -> PageModel | list[dict[str, Any] | list[dict[Any, Any]]]:
+        """
+        输入查询语句和分页信息，返回分页数据列表结果
+
+        :param db: orm对象
+        :param query: sqlalchemy查询语句
+        :param page_num: 当前页码
+        :param page_size: 当前页面数据量
+        :param is_page: 是否开启分页
+        :return: 分页数据对象
+        """
+        if is_page:
+            total = (await db.execute(select(func.count('*')).select_from(query.subquery()))).scalar()
+            query_result = await db.execute(query.offset((page_num - 1) * page_size).limit(page_size))
+            paginated_data: list[Row] = []
+            for row in query_result:
+                if row and len(row) == 1:
+                    paginated_data.append(row[0])
+                else:
+                    paginated_data.append(row)
+            has_next = math.ceil(total / page_size) > page_num
+            result = PageModel[Any](
+                rows=CamelCaseUtil.transform_result(paginated_data),
+                pageNum=page_num,
+                pageSize=page_size,
+                total=total,
+                hasNext=has_next,
+            )
+        else:
+            query_result = await db.execute(query)
+            no_paginated_data: list[Row] = []
+            for row in query_result:
+                if row and len(row) == 1:
+                    no_paginated_data.append(row[0])
+                else:
+                    no_paginated_data.append(row)
+            result = CamelCaseUtil.transform_result(no_paginated_data)
+
+        return result
+
+
+def get_page_obj(data_list: list, page_num: int, page_size: int) -> PageModel:
+    """
+    输入数据列表data_list和分页信息，返回分页数据列表结果
+
+    :param data_list: 原始数据列表
+    :param page_num: 当前页码
+    :param page_size: 当前页面数据量
+    :return: 分页数据对象
+    """
+    # 计算起始索引和结束索引
+    start = (page_num - 1) * page_size
+    end = page_num * page_size
+
+    # 根据计算得到的起始索引和结束索引对数据列表进行切片
+    paginated_data = data_list[start:end]
+    has_next = math.ceil(len(data_list) / page_size) > page_num
+
+    result = PageModel[Any](
+        rows=paginated_data, pageNum=page_num, pageSize=page_size, total=len(data_list), hasNext=has_next
+    )
+
+    return result