Flask-Sqlalchemy + Sqlalchemy-searchable returning empty list

Question

First time on the site, so hi to all and thanks in advance. Longtime lurker and newb.

I\'m working on a web app in flask, using Flask-SqlAlchemy and SqlAlchemy-Searchabl

Answer 1

I ran into this exact issue once, too, when using Flask-Script to add a manage.py management tool to my application.

The fact that the search_vector column is empty despite you having added the appropriate TSVectorType parameters means that the SQLAlchemy-Searchable trigger isn't present in the postgres DB. You can verify its absence by doing a \df+ in psql command line tool -- you will not see a trigger named article_search_vector_update. SQLAlchemy-Searchable sets up this trigger to update the content of the search_vector column when the columns named in TSVectorType(...) change.

In the case of manage.py, I had to first call:

db.configure_mappers()

Essentially, you have to configure SQLAlchemy's mappers before calling create_all(). Without doing this, SQLAlchemy-Searchable will not be given the opportunity to add its search_vector trigger to populate the TSVectorType column in the model.The SQLAlchemy-Searchable docs have more on this.

In total, a minimal manage.py that properly configures SQLAlchemy-Searchable as you require might look like:

#!/usr/bin/env python

from flask.ext.script import Manager
from app import app, db

manager = Manager(app)

@manager.command
def init_db():
    """
    Drops and re-creates the SQL schema
    """
    db.drop_all()
    db.configure_mappers()
    db.create_all()
    db.session.commit()