新手尝试根据级联下拉列表过滤返回的项目。 得到以下错误: NotImplementedError:此表达式不支持运算符'getitem'
下面的代码
`Class Asset(db.Model): “” 资产表 “” __tablename_ ='资产'
inv_id = db.Column(db.String(15), primary_key=True)
descript = db.Column(db.String(50))
station = db.Column(db.String(3))
inv_class = db.Column(db.String(10))
@admin.route('/assets', methods=['GET', 'POST'])
@login_required
def list_assets():
form = Form()
form.station.choices = [(Asset.station) for station in
Asset.query.filter_by(inv_class='HOSE').all()]
class Form(FlaskForm):
inv_class = SelectField('inv_class', choices = [])
station = SelectField('station', choices = [])
<body>
<form method="GET","POST">
{{ form.inv_class }}
{{ form.station }}
</form>
</body>
“拳头”下拉列表应按站第二个过滤到inv_class,然后返回包含两者的资产列表。