Flask Python Flask-SQLAlchemy中数据库的数据类型、flask中数据可的列约束配置-编程知识

Flask Python Flask-SQLAlchemy中数据库的数据类型、flask中数据可的列约束配置

SQLAlchemy官方文档地址
实战的代码分享
数据类型
列约束配置
自定义方法

SQLAlchemy官方文档地址

实战的代码分享

Flask-SQLAlchemy框架为创建数据库的实例提供了一个基类及一系列辅助类和辅助函数，用于定于数据库模型的结构，如下：

from project.extension import db
from datetime import datetime
from typing import List
from sqlalchemy import Integer, String, DateTime, Text
from sqlalchemy.orm import Mapped, mapped_column, relationship
from project.personal.model import  User#资源内容模型
class Resource(db.Model):  # 所有的数据库模型均继承自 db.Model 类__tablename__ = 'resource_copy1' # 一般会指定表名，虽然有默认机制，但不一定是我们想要的结果id: Mapped[int] = mapped_column(Integer, primary_key=True, nullable=False, autoincrement=True) # 类变量代表表的列名r_type: Mapped[int] = mapped_column(Integer, nullable=False, default=0)dept_id: Mapped[int] = mapped_column(Integer, nullable=False)title: Mapped[str] = mapped_column(String(50), nullable=False)published_time: Mapped[str] = mapped_column(String(50), nullable=False)publisher_book_name: Mapped[str] = mapped_column(String(50))like_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)view_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)content: Mapped[str] = mapped_column(Text)created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.now)updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.now, onupdate=datetime.now)deptss: Mapped['Dept'] = relationship('Dept', foreign_keys=[dept_id],primaryjoin='Dept.id == Resource.dept_id')# id = db.Column(db.INTEGER, primary_key=True, autoincrement=True)# r_type = db.Column(db.INTEGER, default=0, comment='resource type 0 文献 1 指南 2 大会')# is_show = db.Column(db.INTEGER, default=0, comment='是否上架 0 未上架 1 上架')# title = db.Column(db.String(40))# desc = db.Column(db.TEXT)# cover = db.Column(db.String(40))# published_time = db.Column(db.String(40))# content = db.Column(db.TEXT)# file_path = db.Column(db.String(128))# origin_link = db.Column(db.String(128))# view_count = db.Column(db.INTEGER)# like_count = db.Column(db.INTEGER)# collect_count = db.Column(db.INTEGER)# file_size = db.Column(db.String(40))# publisher_book_name = db.Column(db.String(40))# resource_type_id = db.Column(db.INTEGER)def to_format(self):return {"id": self.id,"title": self.title,"published_time": self.published_time,"view_count": self.view_count,"publisher_book_name": self.publisher_book_name,"dept_name": self.deptss.name,"dept_en_name": self.deptss.english_name}def __init__(self, title, r_type):self.title = titleself.r_type = r_type# 用于输出该类的对象被print()时输出的字符串def __repr__(self) -> str:return f'<Resource id={self.id} title={self.title} r_type={self.r_type}>'