Flask admin: sqlalchemy.exc.InterfaceError (error binding parameter 8)

Question

I tried to save the project reviewer using below, and the select field shows correctly:

# Query the user with Role.id == 4 as reviewer def reviewer_choices(): return User.query.join(User.roles).filter(Role.id == 4) # Build a select field class ProjectView(sqla.ModelView): form_extra_fields = { 'reviewer': sqla.fields.QuerySelectField( label='Reviewer', query_factory=reviewer_choices, )} 

However, when I tried to save it, an error occurred:

InterfaceError: (sqlite3.InterfaceError) Error binding parameter 8 - probably unsupported type. [SQL: u'INSERT INTO project(...reviewer...)VALUES(...<__main__.User object at 0x00000000048E89E8>...) InterfaceError: (sqlite3.InterfaceError) Error binding parameter 8 - probably unsupported type. [SQL: u'INSERT INTO project(...reviewer...)VALUES(...<__main__.User object at 0x00000000048E89E8>...) .

And I noticed that the reviewer is an object, something like: <__main__.User object at 0x00000000048E89E8> . So, what is the correct reviewer data type so I can save it to the database? I am currently using:

In the project class

 class Project(db.Model): # ... reviewer = db.Column(db.Unicode(128)) # ... 

In the project table

 CREATE TABLE `project` ( # ... `reviewer1` TEXT, # ... 

And I also tried to define __repr__ and __str__ , but both did not work:

 class User(db.Model, UserMixin): id = db.Column(db.Integer, primary_key=True) first_name = db.Column(db.String(255)) # ... # ... def __repr__(self): return self.first_name class User(db.Model, UserMixin): id = db.Column(db.Integer, primary_key=True) first_name = db.Column(db.String(255)) # ... # ... def __str__(self): return self.first_name 

Answer 1

It is obvious. A reviewer is a line defined in a project. You can define the __repr__ function in the User model to return a string (username or something else). Check out the question .