anodb 11.0

Convenient Wrapper around AioSQL and a Database Connection

AnoDB

Convenient Wrapper around aiosql and a Database Connection.

Description

This class creates a persistent database connection and imports SQL queries from a file as simple Python functions.

If the connection is broken, a new connection is attempted with increasing throttling delays.

Compared to aiosql, the point is not to need to pass a connection as an argument on each call: The DB class embeds both connection and query methods.

For concurrent programming (threads, greenlets…), a relevant setup should also consider thread-locals and pooling issues at some higher level.

Example

Install the module with pip install anodb or whatever method you like. Once available:

import anodb
# parameters: driver, connection string, SQL file
db = anodb.DB("sqlite3", "test.db", "test.sql", kwargs_only=True)

db.create_stuff()
db.do_some_insert(key=1, val="hello")
db.do_some_update(key=1, val="world")
print("data", db.do_some_select(key=1))
print("norm", db.compute_norm(c=3+4j))
db.commit()

db.close()

With file test.sql containing something like:

-- name: create_stuff#
CREATE TABLE Stuff(key INTEGER PRIMARY KEY, val TEXT NOT NULL);

-- name: do_some_select^
SELECT * FROM Stuff WHERE key = :key;

-- name: do_some_insert!
INSERT INTO Stuff(key, val) VALUES (:key, :val);

-- name: do_some_update!
UPDATE Stuff SET val = :val WHERE key = :key;

-- name: compute-norm$
SELECT SQRT(:c.real * :c.real + :c.imag * :c.imag);

Documentation

The anodb module provides the DB class which embeds both a PEP 249 database connection (providing methods commit, rollback, cursor, close and its connect counterpart to re-connect) and SQL queries wrapped into dynamically generated functions by aiosql. Such functions may be loaded from a string (add_queries_from_str) or a path (add_queries_from_path).

The DB constructor parameters are:

• db the name of the database driver: sqlite3, psycopg, pymysql, see aiosql documentation for a list of supported drivers.
• conn an optional connection string used to initiate a connection with the driver. For instance, psycopg accepts a libpq connection string such as: "host=db1.my.org port=5432 dbname=acme user=calvin …".
• queries a path name or list of path names from which to read query definitions.
• options a dictionary or string to pass additional connection parameters.
• auto_reconnect whether to attempt a reconnection if the connection is lost. Default is True. Reconnection attempts are throttled exponentially following powers of two delays from 0.001 and capped at 30.0 seconds.
• kwargs_only whether to only accept named parameters to python functions.
• attribute attribute dot access substition, default is "__", use None to disable.
• exception function to re-process database exceptions.
• debug whether to generate debugging messages. Default is False.
• other named parameters are passed as additional connection parameters.

import anodb

db = anodb.DB("sqlite3", "acme.db", "acme-queries.sql")
db = anodb.DB("duckdb", "acme.db", "acme-queries.sql")
db = anodb.DB("psycopg", "host=localhost dbname=acme", "acme-queries.sql")
db = anodb.DB("psycopg", None, "acme-queries.sql", host="localhost", user="calvin", password="...", dbname="acme")
db = anodb.DB("psycopg2", "host=localhost dbname=acme", "acme-queries.sql")
db = anodb.DB("pygresql", None, "acme-queries.sql", host="localhost:5432", user="calvin", password="...", database="acme")
db = anodb.DB("pg8000", None, "acme-queries.sql", host="localhost", port=5432, user="calvin", password="...", database="acme")
db = anodb.DB("MySQLdb", None, "acme-queries.sql", host="localhost", port=3306, user="calvin", password="...", database="acme")
db = anodb.DB("pymysql", None, "acme-queries.sql", host="localhost", port=3306, user="calvin", password="...", database="acme")
db = anodb.DB("mysql-connector", None, "acme-queries.sql", host="localhost", port=3306, user="calvin", password="...", database="acme")
db = anodb.DB("mariadb", None, "acme-queries.sql", host="localhost", port=3306, user="calvin", password="...", database="acme")

License

This code is Public Domain.

All software has bug, this is software, hence… Beware that you may lose your hairs or your friends because of it. If you like it, feel free to send a postcard to the author.

Versions

Sources, documentation and issues are available on GitHub.

See all versions and get packages from PyPI.