anodb 10.4

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")

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))
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;

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.

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Versions

Sources, documentation and issues are available on GitHub.

See all versions and get packages from PyPI.