#!/usr/bin/python # -*- coding: utf-8 -*- # @version : 1.0 # @Creaet Time : 2021/10/18 22:18 # @File : crud.py # @IDE : PyCharm # @desc : 数据库 增删改查操作 # sqlalchemy 查询操作：https://segmentfault.com/a/1190000016767008 # SQLAlchemy lazy load和eager load: https://www.jianshu.com/p/dfad7c08c57a # Mysql中内连接,左连接和右连接的区别总结:https://www.cnblogs.com/restartyang/articles/9080993.html # SQLAlchemy join 内连接 # selectinload 官方文档： # https://www.osgeo.cn/sqlalchemy/orm/loading_relationships.html?highlight=selectinload#sqlalchemy.orm.selectinload from typing import List from fastapi import HTTPException from fastapi.encoders import jsonable_encoder from sqlalchemy import func, delete, and_ from sqlalchemy.future import select from sqlalchemy.ext.asyncio import AsyncSession from sqlalchemy.orm import selectinload from starlette import status from core.logger import logger from sqlalchemy.sql.selectable import Select class DalBase: def __init__(self, db: AsyncSession, model, schema, key_models: dict = None): self.db = db self.model = model self.schema = schema self.key_models = key_models async def get_data(self, data_id: int = None, options: list = None, schema=None, keys: dict = None, **kwargs): """ 获取单个数据，默认使用 ID 查询，否则使用关键词查询 :param data_id: :param keys: 外键字段查询，内连接 :param options: 指示应使用select在预加载中加载给定的属性。 :param schema: 指定使用的序列化对象 :param kwargs: 关键词参数, :param kwargs: order，排序，默认正序，为 desc 是倒叙 :param kwargs: return_none，是否返回空 None，否认 抛出异常，默认抛出异常 """ order = kwargs.get("order", None) return_none = kwargs.get("return_none", False) keys_exist = False if keys: for key, value in keys.items(): if value and isinstance(value, dict): for k, v in value.items(): if v: keys_exist = True break kwargs_exist = False if kwargs: for key, value in kwargs.items(): if key != "order" and key != "return_none" and value and getattr(self.model, key, None): kwargs_exist = True break if data_id or kwargs_exist or keys_exist: sql = select(self.model).where(self.model.id == data_id) if data_id else select(self.model) sql = self.add_filter_condition(sql, keys, options, **kwargs) else: sql = select(self.model) if order and order == "desc": sql = sql.order_by(self.model.create_datetime.desc()) queryset = await self.db.execute(sql) data = queryset.scalars().first() if not data and return_none: return None if data and schema: return schema.from_orm(data).dict() if data: return data raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="未找到此数据") async def get_datas(self, page: int = 1, limit: int = 10, keys: dict = None, options: list = None , schema=None, **kwargs): """ 获取数据列表 :param page: 页码 :param limit: 当前页数据量 :param keys: 外键字段查询 :param options: 指示应使用select在预加载中加载给定的属性。 :param schema: 指定使用的序列化对象 :param kwargs: order，排序，默认正序，为 desc 是倒叙 :param kwargs: order_field，排序字段 :param kwargs: return_objs，是否返回对象 :param kwargs: start_sql，初始 sql """ order = kwargs.get("order", None) order_field = kwargs.get("order_field", None) return_objs = kwargs.get("return_objs", False) start_sql = kwargs.get("start_sql", None) sql = self.add_filter_condition(start_sql if isinstance(start_sql, Select) else select(self.model), keys, options, **kwargs) if order_field and order == "desc": sql = sql.order_by(getattr(self.model, order_field).desc(), self.model.id.desc()) elif order_field: sql = sql.order_by(getattr(self.model, order_field), self.model.id) elif order == "desc": sql = sql.order_by(self.model.id.desc()) if limit != 0: sql = sql.offset((page - 1) * limit).limit(limit) queryset = await self.db.execute(sql) if return_objs: return queryset.scalars().all() if schema: return [schema.from_orm(i).dict() for i in queryset.scalars().all()] return [self.out_dict(i) for i in queryset.scalars().all()] async def get_count(self, keys: dict = None, **kwargs): """获取数据总数""" sql = select(func.count(self.model.id).label('total')) sql = self.add_filter_condition(sql, keys, **kwargs) queryset = await self.db.execute(sql) return queryset.one()['total'] async def create_data(self, data, return_obj: bool = False, options: list = None, schema=None): """创建数据""" if isinstance(data, dict): obj = self.model(**data) else: obj = self.model(**data.dict()) self.db.add(obj) await self.db.flush() await self.db.refresh(obj) if options: obj = await self.get_data(obj.id, options=options) if return_obj: return obj if schema: return schema.from_orm(obj).dict() return self.out_dict(obj) async def put_data(self, data_id: int, data, return_obj: bool = False, options: list = None, schema=None): """ 更新单个数据 """ obj = await self.get_data(data_id, options=options) obj_dict = jsonable_encoder(data) for key, value in obj_dict.items(): setattr(obj, key, value) await self.db.flush() await self.db.refresh(obj) if return_obj: return obj if schema: return schema.from_orm(obj).dict() return self.out_dict(obj) async def delete_datas(self, ids: List[int]): """ 删除多个数据 """ for data_id in ids: await self.db.execute(delete(self.model).where(self.model.id == data_id)) def add_filter_condition(self, sql: select, keys: dict = None, options: list = None, **kwargs) -> select: """ 添加过滤条件，以及内连接过滤条件 :param sql: :param keys: 外键字段查询，内连接 :param options: 指示应使用select在预加载中加载给定的属性。 :param kwargs: 关键词参数 """ if keys and self.key_models: for key, value in keys.items(): model = self.key_models.get(key) if model: sql = sql.join(model) for v_key, v_value in value.items(): if v_value is not None and v_value != "": v_attr = getattr(model, v_key, None) if not v_attr: continue if isinstance(v_value, tuple): if v_value[0] == "date": # 根据日期查询， 关键函数是：func.time_format和func.date_format sql = sql.where(func.date_format(v_attr, "%Y-%m-%d") == v_value[1]) elif v_value[0] == "like": sql = sql.where(v_attr.like(f"%{v_value[1]}%")) else: sql = sql.where(v_attr == v_value) else: logger.error(f"外键查询报错：{key}模型不存在，无法进行下一步查询。") elif keys and not self.key_models: logger.error(f"外键查询报错：key_models 外键模型无配置项，无法进行下一步查询。") for field in kwargs: value = kwargs.get(field) if value is not None and value != "": attr = getattr(self.model, field, None) if not attr: continue if isinstance(value, tuple): if value[0] == "date": # 根据日期查询， 关键函数是：func.time_format和func.date_format sql = sql.where(func.date_format(attr, "%Y-%m-%d") == value[1]) elif value[0] == "like": sql = sql.where(attr.like(f"%{value[1]}%")) else: sql = sql.where(attr == value) if options: sql = sql.options(*[selectinload(i) for i in options]) return sql def out_dict(self, data): """ 序列化 :param data: :return: """ return self.schema.from_orm(data).dict()