标签：session name author flask db 案例 book id 图书

后台

from flask import Flask, render_template, request, flash, redirect, url_for
from flask_sqlalchemy import SQLAlchemy
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import InputRequired, DataRequired

app = Flask(__name__)
app.secret_key = 'asdffsdaf1111sdfa11sdfdsa'
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:3Dmax2012#@127.0.0.1:3306/test3'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)


class AddBook(FlaskForm):
    author_name = StringField(label='作者名字', validators=[InputRequired()])
    book_name = StringField(label='书籍名称', validators=[DataRequired()])
    submit = SubmitField('调价')


class Author(db.Model):
    __tablename__ = 'authors'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    name = db.Column(db.String(64), unique=True)
    books = db.relationship('Book', backref='author')


class Book(db.Model):
    __tablename__ = 'books'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    name = db.Column(db.String(64), unique=True)
    author_id = db.Column(db.Integer, db.ForeignKey(Author.id))


@app.route("/", methods=['GET', 'POST'])
def index():
    # 使用wtf 表单
    bookform = AddBook()
    # 增加书籍
    if request.method == 'POST':
        if bookform.validate_on_submit():
            author_name = request.form.get('author_name')
            book_name = request.form.get('book_name')
            author = Author.query.filter(Author.name == author_name).first()
            book = Book.query.filter(Book.name == book_name).first()
            if not author:
                try:
                    author = Author(name=author_name)
                    db.session.add(author)
                    db.session.commit()
                except Exception as e:
                    db.session.rollback()
                    print(e)

            if not book:
                try:
                    book = Book(name=book_name, author_id=author.id)
                    db.session.add(book)
                    db.session.commit()
                except Exception as e:
                    db.session.rollback()
                    print(e)
                    flash("添加失败")
            else:
                flash('你输入的已经重复')
        else:
            # if request.method=='POST':
            flash("参数错误")

    # 查询数据
    authors = Author.query.filter(Author.id.in_((book.author_id for book in Book.query.all())))
    # 渲染模板
    return render_template('template8.html', authors=authors, form=bookform)


@app.route('/delete/author/<author_id>')
def delauthor(author_id):
    #  根据author_id 查询 作者
    #  如果存在，就直接删除作者及其书籍
    #  若果不存在，则返回不存在
    author = Author.query.get(author_id)
    if not author:
        return "作者不存在"

    try:
        for book in author.books:
            db.session.delete(author)
        db.session.delete(author)
        db.session.commit()
    except Exception as e:
        print(e)
        db.session.rollback()
        return '删除作者书籍失败'
    return redirect(url_for("index"))


@app.route("/delete/book/<book_id>")
def delbook(book_id):
    # 根据author_id,book_id 查询 作者,书籍
    # 如果存在，就直接删除作者及其书籍
    # 返回参数不合法
    # 若果不存在，则返回不存在
    book = Book.query.filter(Book.id == book_id).first()
    if not book:
        return "书籍不存在"
    try:
        db.session.delete(book)
        db.session.commit()
    except Exception as e:
        db.session.rollback()
        print(e)
    return redirect(url_for("index"))


if __name__ == '__main__':
    db.drop_all()
    db.create_all()
    au1 = Author(name='老王')
    au2 = Author(name='老尹')
    au3 = Author(name='老刘')
    # 把数据提交给用户会话
    db.session.add_all([au1, au2, au3])
    # 提交会话
    db.session.commit()
    bk1 = Book(name='老王回忆录', author_id=au1.id)
    bk2 = Book(name='我读书少，你别骗我', author_id=au1.id)
    bk3 = Book(name='如何才能让自己更骚', author_id=au2.id)
    bk4 = Book(name='怎样征服美丽少女', author_id=au3.id)
    bk5 = Book(name='如何征服英俊少男', author_id=au3.id)
    # 把数据提交给用户会话
    db.session.add_all([bk1, bk2, bk3, bk4, bk5])
    # 提交会话
    db.session.commit()

    app.run(debug=True)

模板文件

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<form action="" method="post">
    {{ form.csrf_token }}
    {{ form.author_name.label }} {{ form.author_name }}  <br>
    {{ form.book_name.label }} {{ form.book_name }}  <br>
    {{ form.submit }}
</form>
{% for message in get_flashed_messages() %}
    {{ message }}
{% endfor %}
<ul>
    {% for author in authors %}
     <li>
        {{ author.name }} <a href="/delete/author/{{ author.id }}">删除</a>
     </li>
         <ul>
             {% for book in author.books %}
                <li>{{ book.name }}  <a href="/delete/book/{{ book.id }}">删除</a></li>
             {% endfor %}
         </ul>
    {% endfor %}


</ul>
</body>
</html>

标签：session,name,author,flask,db,案例,book,id,图书
来源： https://www.cnblogs.com/kxtomato/p/16345719.html

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