duckql 0.13.0

JSON declarative SQL conversion library

duckQL 🐥

duckQL is simple JSON-based notation for some SQL dialects (PostgreSQL, MariaDB, MySQL) based on pydantic library.

Example

Here is a simple example of library usage. For more examples please visit project page.

from duckql import Query, Property, Comparision, Constant


my_query = Query(
    entity='users',
    properties=[
        Property(name='users.name'),
        Property(name='users.surname')
    ],
    conditions=Comparision(
        properties=[
            Property(name='users.age'),
            Constant(value=15)
        ],
        operation=Comparision.Operation.GREATER_EQUAL
    )
)

{
  "obj": "structures.Query",
  "entity": "users",
  "properties": [
    {
      "obj": "properties.Property",
      "name": "users.name"
    },
    {
      "obj": "properties.Property",
      "name": "users.surname"
    }
  ],
  "conditions": {
    "obj": "structures.Comparision",
    "properties": [
      {
        "obj": "properties.Property",
        "name": "users.age"
      },
      {
        "obj": "properties.Constant",
        "value": "15"
      }
    ],
    "operation": "gte"
  }
}

SELECT users.name, users.surname FROM users WHERE (users.age >= 15);

Development

Project is using poetry and documentation is generated by MkDocs. If you want to generate documentation you need to follow these simple steps inside of your virtual environment:

1. poetry install
2. mkdocs build

Inside of your virtual environment, you can also use mkdocs serve to create temporary auto-reload http server with live docs.

We use pytest for unit tests and flake8 for code-style validation. You can execute tests inside of pipenv shell using these commands:

• pytest -v .: executes unit tests
• pytest -v --flake8 .: flake8 code-style tests

License

---

Made with ☕️ and ❤️ by Jakub Dubec & BACKBONE s.r.o.

Changelog

0.13.0 : 2022-06-09

• Added: Ability to use casting for ORDER BY property

0.12.1 : 2022-05-10

• Fixed: Corrected cast of JSON fields

0.12.0 : 2021-12-21

• Feature: FirstValue window function introduced
• Feature: Positional ArrayAgg introduced

0.11.1 : 2021-12-14

• Change: Ability to cast to UUID

0.11.0 : 2021-12-10

• Feature: More benevolent type nesting

0.10.0 : 2021-11-30

• Feature: Case introduced (without docs, there was no time, sry, let's call it Easter Egg for a while)

0.9.1 : 2021-07-20

• Fix: Fixed problem with multiple properties in operations (I had to remove comparison property check)

0.9.0 : 2021-06-25

• Fix: Fixed nested conditions (Operator can contain another Operator)
• Change: Dropped Python 3.6 support

0.8.2 : 2020-10-15

• Fix: Use -> instead of -->

0.8.1 : 2020-10-15

• Fix: Use --> operator in JSON lookup chaining in nested objects

0.8.0 : 2020-10-14

• Feature: Nested JSON fields

0.7.2 : 2020-08-28

• Fix: Use ->> operator in JSON lookup instead of -> (cast result as text)

0.7.1 : 2020-08-27

• Fix: Use quotes in JSON column type keys in Property

0.7.0 : 2020-08-27

• Feature: Now is possible to pass Distinct to Count to have COUNT(DISTINCT property) syntax in pSQL
• Tests: Test for JSON column type in pSQL

0.6.1 : 2020-08-04

• Fix: Use native typing.Literal if possible (Python 3.8 compatibility fix)

0.6.0 : 2020-07-23

• Feature: lower function introduced
• Feature: upper function introduced
• Feature: pSQL initcap function introduced

0.5.0 : 2020-07-22

• Feature: QueryFactory supporting json, msgpack and bson
• Feature: pSQL unaccent function introduced

0.4.0 : 2020-06-12

• Feature: Extract.Unit.DAY introduced
• Feature: CastOperator.DataType.REAL introduced
• Feature: pSQL to_char function introduced
• Feature: pSQL to_date function introduced

0.3.0 : 2020-05-20

• Feature: HAVING support
• Feature: NOW() support
• Fix: Comparision allows to have every BaseType as properties
• Fix: Interval value is quoted now

0.2.2 : 2020-04-16

• Change: Ability to pass structures.Distinct into functions.StringAgg

0.2.1 : 2020-04-09

• Fix: Fixed JOIN aliases

0.2.0 : 2020-04-09

Project renamed to duckql, this is the first public release (development status modifier changed to beta).

• Change: Name changed to duckql
• Change: Poetry as package manager

0.1.8 : 2020-04-07

• Feature: Subquery support
• Note: Changelog datetimes in ISO 8601 compatible Y-m-d format

0.1.7 : 2020-03-17

• Fix: Adding missing imports in __init__.py files inside of submodules
• Change: Moved __version__ from __init__.py to version.py
• Note: Development status change to Alpha

0.1.6 : 2020-03-13

• Feature: Introduced functions.StringAgg
• Feature: Introduced structures.CastOperator
• Feature: CLI for parsing files

0.1.5 : 2020-02-05

• Change: Allow direct use of structures.Comparision in query conditions

0.1.4 : 2020-02-05

• Fix: Allow aliases in structures.Query
• Change: Do not escape %

0.1.3 : 2020-02-03

• Feature: Natural join support

0.1.2 : 2020-02-03

• Change: Completed docs
• Feature: Recursive nested properties lookup in Query object

0.1.1 : 2020-02-26

• Change: Default values for optional attributes in structures.Query
• Change: custom_parser now can raise ParseError if there is invalid object type passed

0.1.0 : 2020-02-26

• Initial release