Skip to main content

small and lightweight query builder and data layer based on Pydantic and asyncpg

Project description


qwery is a small and lightweight query builder based on asyncpg and pydantic.

why a query builder

In my opinion query builders strike a great balance between the flexibility of raw SQL, the structure and safety of pre-crafted queries, and the comfortable data layer of an ORM.

These benefits come with some downsides:

  • You lose some flexibility when crafting queries, especially when dealing with things like partial updates.
  • While the query builder interface does provide some typing, its dynamic nature means it can never match the safety of pre-crafted queries with hand-written or generated types.
  • Complex queries returning non-standard data become unruly fast.

model, queries, helper pattern

qwery works best with a model + queries + helper pattern, namely:

  • Models describe only data and how it is stored
  • Queries describe how models interact with the database
  • Helpers describe and implement the interaction between models and the application (creation, fetching, etc)


from pydantic import BaseModel
from qwery import Query

class MyModel(BaseModel):
    class Meta:
        table_name = "my_table"

    id: int
    name: str
    desc: Optional[str]
    active: bool

class MyModelQueries:
    create = Query(MyModel).insert(body=True).execute()
    delete_by_id = Query(MyModel).delete().where("id = {.id}").execute()
    get_by_id = Query(MyModel).select().where("id = {.id}").fetch_one()
    get_all = Query(MyModel).select().fetch_all()

async with pool.acquire() as conn:
    model = MyModel(id=1, name="test", desc=None, active=True)
    await MyModelQueries.create(conn, model=model)

    model = await MyModelQueries.get_by_id(conn, id=1)
    models = await MyModelQueries.get_all(conn)
    assert models == [model]

    await MyModelQueries.delete(conn, id=1)

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

qwery-0.0.10.tar.gz (5.6 kB view hashes)

Uploaded source

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page