Python - SQLAlchemy getting 'Table' object is not callable error

Question

I have defined an existing DB Table in my python script and whenever I tried to insert a row to db table, I receive an error message stating the "Table object is not callable"

Below you can find the code and error message I receive. Any support will be appreciated:

engine = create_engine('postgresql://user:pwd@localhost:5432/dbname', 

client_encoding='utf8')
metadata = MetaData()
MyTable = Table('target_table', metadata, autoload=True, autoload_with=engine)
Session = sessionmaker()
Session.configure(bind=engine)
session = Session()
:
:
:
def recod_to_db(db_hash):
    db_instance = MyTable(**db_hash)
    session.add(db_instance)
    session.commit()
    return

Error Message:

  File "myprog.py", line 319, in recod_to_db
    db_instance = MyTable(**db_hash)
TypeError: 'Table' object is not callable

This is how the table looks like

                                                             Table "public.target_table"
      Column       |            Type             |                       Modifiers                        | Storage  | Stats target | Description 
-------------------+-----------------------------+--------------------------------------------------------+----------+--------------+-------------
 id                | integer                     | not null default nextval('target_table_id_seq'::regclass) | plain    |              | 
 carid             | integer                     |                                                        | plain    |              | 
 triplecode        | character varying           |                                                        | extended |              | 
 lookup            | integer                     |                                                        | plain    |              | 
 type              | character varying           |                                                        | extended |              | 
 make              | character varying           |                                                        | extended |              | 
 series            | character varying           |                                                        | extended |              | 
 model             | character varying           |                                                        | extended |              | 
 year              | integer                     |                                                        | plain    |              | 
 fuel              | character varying           |                                                        | extended |              | 
 transmission      | character varying           |                                                        | extended |              | 
 mileage           | integer                     |                                                        | plain    |              | 
 hp                | integer                     |                                                        | plain    |              | 
 color             | character varying           |                                                        | extended |              | 
 door              | integer                     |                                                        | plain    |              | 
 location          | character varying           |                                                        | extended |              | 
 url               | character varying           |                                                        | extended |              | 
 register_date     | date                        |                                                        | plain    |              | 
 auction_end_time  | timestamp without time zone |                                                        | plain    |              | 
 body_damage       | integer                     |                                                        | plain    |              | 
 mechanical_damage | integer                     |                                                        | plain    |              | 
 target_buy        | integer                     |                                                        | plain    |              | 
 price             | integer                     |                                                        | plain    |              | 
 currency          | character varying           |                                                        | extended |              | 
 auctionid         | integer                     |                                                        | plain    |              | 
 seller            | character varying           |                                                        | extended |              | 
 auction_type      | character varying           |                                                        | extended |              | 
 created_at        | timestamp without time zone | not null                                               | plain    |              | 
 updated_at        | timestamp without time zone | not null                                               | plain    |              | 
 estimated_value   | integer                     |                                                        | plain    |              | 
Indexes:
    "target_table_pkey" PRIMARY KEY, btree (id)

Inside the definition of recod_to_db, you have MyTable(**db_hash). Shouldn't that be Table(**db_hash)? MyTable is an already created object that does not have a __call__ method. In any case, that's what the issue is. — Abdou
– Abdou, Commented Aug 23, 2017 at 17:56
Table is a SQLAlchemy Core concept; you cannot use it to construct an instance of a model and add it to the session (which are ORM concepts). You'll want to use automap to create mapped classes for your tables. — univerio
– univerio, Commented Aug 23, 2017 at 17:57

Chayemor · Accepted Answer · 2019-10-15 11:46:13Z

Another way of inserting without auto_map is using the table's method for insert. Documentation is here

insert(dml, values=None, inline=False, **kwargs) Generate an insert() construct against this TableClause.

E.g.:

table.insert().values(name='foo')

In code it would look like this:

  def record_to_db(MyTable):
      insert_stmnt = MyTable.insert().values(column_name=value_you_want_to_insert)
      session.execute(insert_stmnt) 

      session.commit()
      return

Ideally, you'd have your table defined in a separate folder other than in your app.py. You can also have utils functions that yields the session and then commits or catches an exception and that a rollback on it. Something like this:

def get_db_session_scope(sql_db_session):
    session = sql_db_session()
    try:
        yield session
        session.commit()
    except:
        session.rollback()
        raise
    finally:
        session.close()

Then your function would look like this:

def record_to_db(MyTable):
      with get_db_session_scope(db) as db_session:
          insert_stmnt = 
MyTable.insert().values(column_name=value_you_want_to_insert)
          session.execute(insert_stmnt) 

      return

You can get db from your app.py through

from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy(app)

Collectives™ on Stack Overflow

Python - SQLAlchemy getting 'Table' object is not callable error

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related