Flask-WTF和Flask-SQLAlchemy都是很好用的插件，然而当它们结合到一起后，就不是那么美妙了。

问题的提出

在models.py中定义了一个Article、Category和Tag类：

12345678910111213141516171819202122232425262728293031323334353637 class Article(db.Model):    \”\”\”定义文章\”\”\”     __tablename__ = \’articles\’    id = db.Column(db.Integer, primary_key=True)    title = db.Column(db.String(128), unique=True, index=True)    # 保存md格式的文本    content = db.Column(db.Text)    # 保存html格式的文本    content_html = db.Column(db.Text)    # 文章分类    category_id = db.Column(db.Integer, db.ForeignKey(\’categories.id\’))    # 文章标签    tags = db.relationship(        \’Tag\’, secondary=\’article_tag_ref\’, backref=\’articles\’)class Category(db.Model):    \”\”\”文章分类\”\”\”     __tablename__ = \’categories\’    id = db.Column(db.Integer, primary_key=True)    name = db.Column(db.String(128), unique=True)    articles = db.relationship(\’Article\’, backref=\’category\’, lazy=\’dynamic\’) class Tag(db.Model):    \”\”\”文章标签\”\”\”     __tablename__ = \’tags\’    id = db.Column(db.Integer, primary_key=True)    name = db.Column(db.String(128), unique=True) # 文章和标签的映射表 ，多对多关系article_tag_ref = db.Table(\’article_tag_ref\’,                           db.Column(\’article_id\’, db.Integer,                                     db.ForeignKey(\’articles.id\’)),                           db.Column(\’tag_id\’,  db.Integer,                                     db.ForeignKey(\’tags.id\’))                           )

 

然后在forms.py中定义一个ArticleForm表单

1234567 class ArticleForm(Form):     title = StringField(u\”标题\”, validators=[Required()])    category = QuerySelectField(u\”分类\”, query_factory=getUserFactory([\’id\’, \’name\’]), get_label=\’name\’)    tags = StringField(u\”标签\”, validators=[Required()])    content = PageDownField(u\”正文\”, validators=[Required()])    submit = SubmitField(u\”发布\”)

此时在处理表单的时候可以这样：

1234 form = ArticleForm()if form.validate_on_submit():    article = Article(title=from.data.title, content=form.data.content,category=form.category.data)4d931186537\” class=\”crayon-syntax crayon-theme-github crayon-font-monaco crayon-os-pc print-yes notranslate\” data-settings=\” minimize scroll-always\” style=\” margin-top: 12px; margin-bottom: 12px; font-size: 13px !important; line-height: 15px !important;\”>

12345678910111213141516171819202122232425262728293031323334353637 class Article(db.Model):    \”\”\”定义文章\”\”\”     __tablename__ = \’articles\’    id = db.Column(db.Integer, primary_key=True)    title = db.Column(db.String(128), unique=True, index=True)    # 保存md格式的文本    content = db.Column(db.Text)    # 保存html格式的文本    content_html = db.Column(db.Text)    # 文章分类    category_id = db.Column(db.Integer, db.ForeignKey(\’categories.id\’))    # 文章标签    tags = db.relationship(        \’Tag\’, secondary=\’article_tag_ref\’, backref=\’articles\’)class Category(db.Model):    \”\”\”文章分类\”\”\”     __tablename__ = \’categories\’    id = db.Column(db.Integer, primary_key=True)    name = db.Column(db.String(128), unique=True)    articles = db.relationship(\’Article\’, backref=\’category\’, lazy=\’dynamic\’) class Tag(db.Model):    \”\”\”文章标签\”\”\”     __tablename__ = \’tags\’    id = db.Column(db.Integer, primary_key=True)    name = db.Column(db.String(128), unique=True) # 文章和标签的映射表 ，多对多关系article_tag_ref = db.Table(\’article_tag_ref\’,                           db.Column(\’article_id\’, db.Integer,                                     db.ForeignKey(\’articles.id\’)),                           db.Column(\’tag_id\’,  db.Integer,                                     db.ForeignKey(\’tags.id\’))                           )

 

然后在forms.py中定义一个ArticleForm表单

1234567 class ArticleForm(Form):     title = StringField(u\”标题\”, validators=[Required()])    category = QuerySelectField(u\”分类\”, query_factory=getUserFactory([\’id\’, \’name\’]), get_label=\’name\’)    tags = StringField(u\”标签\”, validators=[Required()])    content = PageDownField(u\”正文\”, validators=[Required()])    submit = SubmitField(u\”发布\”)

此时在处理表单的时候可以这样：

1234 form = ArticleForm()if form.validate_on_submit():    article = Article(title=from.data.title, content=form.data.content,category=form.category.data)span class=\”crayon-h\”>    ...

等等，这样怎么处理form.data.tags？只有像下面这样写了：