anosql

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A Python library for using SQL

Inspired by the excellent Yesql library by Kris Jenkins. In my mother tongue, ano means yes.

Installation

$ pip install anosql

Usage

Basics

Given a queries.sql file:

-- name: get-all-greetings
-- Get all the greetings in the database
SELECT * FROM greetings;

We can issue SQL queries, like so:

import anosql
import psycopg2
import sqlite3

# PostgreSQL
conn = psycopg2.connect('...')
queries = anosql.load_queries('postgres', 'queries.sql')

# Or, Sqlite3...
conn = sqlite3.connect('cool.db')
queries = anosql.load_queries('sqlite', 'queries.sql')

queries = queries.get_all_greetings(conn)
# => [(1, 'Hi')]

queries.get_all_greetings.__doc__
# => Get all the greetings in the database

queries.get_all_greetings.__query__
# => SELECT * FROM greetings;

queries.available_queries
# => ['get_all_greetings']

Parameters

Often, you want to change parts of the query dynamically, particularly values in the WHERE clause. You can use parameters to do this:

-- name: get-greetings-for-language-and-length
-- Get all the greetings in the database
SELECT *
FROM greetings
WHERE lang = %s;

And they become positional parameters:

visitor_language = "en"
queries.get_all_greetings(conn, visitor_language)

Named Parameters

To make queries with many parameters more understandable and maintainable, you can give the parameters names:

-- name: get-greetings-for-language-and-length
-- Get all the greetings in the database
SELECT *
FROM greetings
WHERE lang = :lang
AND len(greeting) <= :length_limit;

If you were writing a Postgresql query, you could also format the parameters as %s(lang) and %s(length_limit).

Then, call your queries like you would any Python function with named parameters:

visitor_language = "en"

greetings_for_texting = queries.get_all_greetings(
              conn, lang=visitor_language, length_limit=140)

Update/Insert/Delete

In order to run UPDATE, INSERT, or DELETE statements, you need to add ! to the end of your query name. Anosql will then execute it properly. It will also return the number of affected rows.

Insert queries returning autogenerated values

If you want the auto-generated primary key to be returned after you run an insert query, you can add <! to the end of your query name.

-- name: create-user<!
INSERT INTO person (name) VALUES (:name)

Tests

$ pip install tox
$ tox

Caveats

Postgresql and sqlite only at the moment

License

BSD, short and sweet

perlchild/anosql