entity-query-language 2.0.1

Provides a relational query language that is pythonic and intuitive. Entity Query Language serves as a front end to other query languages like sql or prolog

Entity Query Language (EQL)

EQL is a relational query language that is pythonic, and intuitive.

The interface side of EQL is inspired by euROBIN entity query language white paper.

Installation

pip install entity_query_language

Documentation

Read the documentation here.

Example Usage

An important feature of EQL is that you do not need to do operations like JOIN in SQL, this is performed implicitly. EQL tries to mirror your intent in a query statement with as less boiler plate code as possiple. For example an attribute access with an equality check to another value is as simple as using python's dot notation with the equality operator. For example:

from dataclasses import dataclass

from typing_extensions import List

from entity_query_language import entity, an, let, contains, symbolic_mode, symbol


@symbol
@dataclass
class Body:
    name: str


@dataclass
class World:
    id_: int
    bodies: List[Body]


world = World(1, [Body("Body1"), Body("Body2")])

with symbolic_mode():
    body = let(type_=Body, domain=world.bodies)
    query = an(entity(body, contains(body.name, "2"),
                      body.name.startswith("Body"))
               )
results = list(query.evaluate())
assert len(results) == 1
assert results[0].name == "Body2"

where this creates a body variable that gets its values from world.bodies, and filters them to have their att "name" equal to "Body1".

To Cite:

@software{bassiouny2025eql,
author = {Bassiouny, Abdelrhman},
title = {Entity-Query-Language},
url = {https://github.com/AbdelrhmanBassiouny/entity_query_language},
version = {2.0.0}
}