Get data values from QuerySelectField with query_factory

问题

I have problem to save data from QuerySelectField with query_factory. I will always end with:

Error message

InterfaceError: (sqlite3.InterfaceError) 
Error binding parameter 2 - probably unsupported type. 
[SQL: u'INSERT INTO asset_objects (asset_name, asset_type, asset_owner)
VALUES (?, ?, ?)'] [parameters: (u'd', u'Process', <__main__.Model_New_Users 
object at 0x03819A50>)]

DB Model

# --- New Information Assets ---
class Model_New_Asset(db.Model):
__tablename__ = 'asset_objects'
id = db.Column('asset_id', db.Integer, primary_key=True)
asset_name = db.Column(db.String(64), unique=False, index=True)
asset_type = db.Column(db.String(64), unique=False, index=True)
asset_owner = db.Column(db.String(64), unique=False, index=True)

def __init__(self, asset_name, asset_type, asset_owner):
    self.asset_name = asset_name
    self.asset_type = asset_type
    self.asset_owner = asset_owner

Form

class Form_New_Asset(Form):
    asset_name = StringField(u'Asset')
    asset_type = SelectField(u'Asset type', 
                             choices=[('Process', 'Process'),
                                      ('Information', 'Information'),
                                      ('Informationssystem', 'Informationssystem'),
                                      ('Applikation', 'Applikation')])
    # From Model_New_Users
    asset_owner = QuerySelectField(u'Owner',
                                   query_factory=lambda: Model_New_Users.query.all(),
                                   get_label='owner_name')
    submit = SubmitField('Save')

Route

@app.route('/add_asset', methods=['GET', 'POST'])
def add_asset():
    form = Form_New_Asset()
    if request.method == 'POST':
        if not request.form['asset_name'] or not request.form['asset_type']:
            flash(u'Fill out all fields...', 'error')
        else:
            add_data = Model_New_Asset(asset_name=form.asset_name.data,
                                       asset_type=form.asset_type.data,
                                       asset_owner=form.asset_owner.data)
           db.session.add(add_data)
           db.session.commit()
           flash('Post saved', 'info')
 ...

It seems that I can't retrieve the actual data from the query_factory function (asset_owner)?

Appreciate your assistance/help!

回答1:

The problem is that you're providing an instance of Model_New_Users as the 2nd (0-indexed) parameter.

InterfaceError: (sqlite3.InterfaceError) 
Error binding parameter 2 - probably unsupported type. 
[SQL: u'INSERT INTO asset_objects (asset_name, asset_type, asset_owner)
VALUES (?, ?, ?)'] [parameters: (u'd', u'Process', <__main__.Model_New_Users object at 0x03819A50>)]

But in your model you've defined it as a String type:

asset_owner = db.Column(db.String(64), unique=False, index=True)

This is queried via a lambda in your form:

asset_owner = QuerySelectField(u'Owner',
                               query_factory=lambda: Model_New_Users.query.all(),
                               get_label='owner_name')

And then the entire object is passed in your update. I think this is the bug.

        add_data = Model_New_Asset(asset_name=form.asset_name.data,
                                   asset_type=form.asset_type.data,
                                   asset_owner=form.asset_owner.data)

I think you can fix it by specifying which field on the Model_New_Users you intend to pass. Something like form.asset_owner.data.owner_name or whatever.

回答2:

The reason you get an instance back is because you haven't given a

def __str__():

representation. Hope this help's newbies like me.

来源：https://stackoverflow.com/questions/41396127/get-data-values-from-queryselectfield-with-query-factory

标签

python

flask-sqlalchemy

wtforms