How to query View in sqlmodel

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Example Code

from typing import Optional

from sqlmodel import Field, Session, SQLModel, create_engine, select

class HeroTeamView(SQLModel):
    name: str
    secret_name: str
    age: Optional[int] = None

sqlite_file_name = "my.db"
db_url = f"mysql+mysqldb://{db_user}:{db_password}@{db_host}:{db_port}/{db_name}"
engine = create_engine(db_url, echo=True)
with Session(engine) as session:
   statement = select(HeroTeamView)
   orgs = session.exec(statement)
   print(f"orgs::{orgs}")
   org_list = orgs.fetchall()

Description

I have a view(Lets say HeroTeamView) created in mysql db. I want to read this. This view is essentially a left join of Hero and Teams table Joined on Hero.Id.

As shown in example above as soon as I try to select This view I get error HeroTeamView is not a 'SQLModelMetaclass' object is not iterable

I am not quiet sure I understand how to access rows created by view

Any pointers appreciated

Operating System

Windows

Operating System Details

No response

SQLModel Version

0.06

Python Version

3.9.7

Additional Context

I dont want to use Hero and Team tables directly to write a select query as there are multiple tables and joins in “real” world problem for me. Using Views provides me some obvious benefits like mentioned here

[byrman]

Am curious about whether your solution indeed just works, or if something else is needed.

I created a view in PostgreSQL:

test=# \d+ teamsandheroes
                                View "public.teamsandheroes"
    Column    |       Type        | Collation | Nullable | Default | Storage  | Description 
--------------+-------------------+-----------+----------+---------+----------+-------------
 id           | integer           |           |          |         | plain    | 
 name         | character varying |           |          |         | extended | 
 secret_name  | character varying |           |          |         | extended | 
 age          | integer           |           |          |         | plain    | 
 team_id      | integer           |           |          |         | plain    | 
 team         | character varying |           |          |         | extended | 
 headquarters | character varying |           |          |         | extended | 
View definition:
 SELECT h.id,
    h.name,
    h.secret_name,
    h.age,
    h.team_id,
    t.name AS team,
    t.headquarters
   FROM hero h
     JOIN team t ON t.id = h.team_id;

Queried it like this:

from sqlmodel import Field, Session, SQLModel, create_engine, select

DB_URL = "postgresql://postgres:postgres@db:5432/test"
engine = create_engine(DB_URL, echo=True)


class HeroTeamView(SQLModel, table=True):
    __tablename__ = "teamsandheroes"

    team_id: int = Field(primary_key=True)
    id: int = Field(primary_key=True)
    name: str
    secret_name: str
    age: int
    team: str
    headquarters: str


def main():
    with Session(engine) as session:
        results = session.exec(select(HeroTeamView))
        for result in results:
            print(result)


if __name__ == "__main__":
    main()

And got this output:

id=1 team_id=1 age=30 secret_name='Dive Wilson' headquarters='Sharp Tower' name='Deadpond' team='Preventers'
id=2 team_id=1 age=20 secret_name='Spider-Boy' headquarters='Sharp Tower' name='Toby Maguire' team='Preventers'

__tablename__ = “viewname” (or did you mean __table__ ?)

The latter gave me a runtime error: AttributeError: 'str' object has no attribute 'c'!?

And if it works, why would you not recommend it?

Personally, I would prefer to interact with individual Hero and Team objects in my code, navigating relationships via properties. Such a HeroTeamView doesn’t feel very natural to me. Counting teams becomes less easy, migration tools might complain, etc. But there might be a use case for this, for example when you don’t have permissions on the individual tables but are allowed to query the view.

[antont]

Right-o, thanks for the info @byrman . We’ve been also happy with relationships, have not planned multi table views.

We looked into using a view to implement the trashcan pattern for a kind of soft delete, like in https://michaeljswart.com/2014/04/implementing-the-recycle-bin-pattern-in-sql/

After some consideration, we didn’t try views (yet), but have just now deleted==None checks in queries and relationships. We’ll see whether stick with that or start using a view later.