ReQueLa, your data assistant!

What is ReQueLa?

ReQueLa is a Python library that allows you to build complex queries to filter and order data in your database. Query are written using RQL, Resource Query Language, a query language expecially designed for RESTful resources.

Installation

pip install requela

Supported RQL operators

Examples

• Filtering: and(eq(name,John),gt(age,30))
• Navigation through relationships using dot notation: eq(account.name,My Account) to filter on a related field.
• Filtering with ANY operator: any(users,eq(users.name,John))
• Ordering: order_by(name,age)
• To order in descendant order, prefix the property name with a minus sign: order_by(-age)
• Combining filtering and ordering: and(eq(name,John),gt(age,30))&order_by(name,age)
• Using logical operators: or(eq(name,John),eq(name,Jane))&order_by(name)
• Using NOT operator: not(eq(name,John))&order_by(name)
• Using LIKE operator with wildcard symbol *: like(name,*John*)
• Using ILIKE operator with wildcard symbol *: ilike(name,*John*)

Usage

Use QueryBuilder directly

SQLAlchemy

from requela import get_builder_for_model

from app.db import get_session
from app.models import MyModel

builder = get_builder_for_model(MyModel)
statement = builder.build_query("and(eq(name,John),gt(age,30))&order_by(name,-age)")

with get_session() as session:
    result = session.execute(statement)
    for model in result:
        print(model)

Django

from requela import get_builder_for_model

from app.models import MyModel

builder = get_builder_for_model(MyModel)
result = builder.build_query("and(eq(name,John),gt(age,30))&order_by(name,-age)")

for model in result:
    print(model)

Create a ModelRQLRules class

You can create a class to specify filtering and ordering rules for a given model like:

from requela import FieldRule, ModelRQLRules, Operator, RelationshipRules
from tests.django.models import Account, User


class AccountRules(ModelRQLRules):
    __model__ = Account

    name = FieldRule()
    description = FieldRule()
    status = FieldRule()
    balance = FieldRule()
    created_at = FieldRule(
        alias="events.created.at",
    )


class UserRules(ModelRQLRules):
    __model__ = User

    name = FieldRule()
    age = FieldRule()
    role = FieldRule(
        allowed_operators=[Operator.IN, Operator.OUT],
    )
    is_active = FieldRule(allow_ordering=False)
    birth_date = FieldRule(
        alias="events.born.at",
    )
    account = RelationshipRules(rules=AccountRules())

    rules = UserRules()
    query = rules.build_query("and(eq(name,John),gt(age,30),eq(events.born.at,2024-01-01))&order_by(name,-age)")

License

ReQueLa is licensed under the Apache 2.0 License and is copyright SoftwareOne AG.