sustained 1.0.2

A Python query builder inspired by Objection.js

Sustained.py

A Python query builder inspired by Objection.js.

Installation

python3 -m pip install sustained

Local Installation from Source

To install sustained from source for local development:

1. Clone the repository:

   git clone https://github.com/wetherc/sustained.git
   cd sustained
   

2. Install in editable mode:

   python3 -m pip install -e .
   

Usage

from sustained import Model, RelationType, create_model

class Person(Model):
    database = 'my_db'
    tableSchema = 'public'
    tableName = 'persons'

class Animal(Model):
    tableName = 'animals'

    relationMappings = {
        'owner': {
            'relation': RelationType.BelongsToOneRelation,
            'modelClass': Person,
            'join': {
                'from': 'animals.ownerId',
                'to': 'persons.id'
            }
        }
    }

# Build a query
query = Animal.query().select('animals.name', 'persons.name').leftOuterJoinRelated('owner')

print(query)
# SELECT animals.name, persons.name
# FROM animals
# LEFT OUTER JOIN persons
#   ON animals.ownerId = persons.id


# Build a more complex query with a CTE and a raw join
active_owners = Person.query().select('id').where('status', '=', 'active')

query = (
    Animal.query()
    .with_('active_owners', active_owners)
    .join('active_owners', 'animals.ownerId', '=', 'active_owners.id')
    .select('animals.name')
)

print(query)
# WITH active_owners AS (
#   SELECT id
#   FROM persons
#   WHERE status = 'active'
# )
# SELECT animals.name
# FROM animals
# JOIN active_owners
#   ON animals.ownerId = active_owners.id

Development

This project uses pre-commit to enforce code quality and run tests before committing code.

Pre-commit Hooks Setup

1. Install pre-commit:

   pip install pre-commit
   

2. Install the Git hooks: From the root of the project directory, run:

   pre-commit install