tableschema-sql-py

Generate and load SQL tables based on Table Schema descriptors.

Features

• implements tableschema.Storage interface
• provides additional features like indexes and updating

Contents

• Getting Started
  • Installation
  • Examples
• Documentation
  • Storage
• Contributing
• Changelog

Getting Started

Installation

The package use semantic versioning. It means that major versions could include breaking changes. It's highly recommended to specify package version range in your setup/requirements file e.g. package>=1.0,<2.0.

pip install tableschema-sql

Examples

Code examples in this readme requires Python 3.3+ interpreter. You could see even more example in examples directory.

from tableschema import Table
from sqlalchemy import create_engine

# Load and save table to SQL
engine = create_engine('sqlite://')
table = Table('data.csv', schema='schema.json')
table.save('data', storage='sql', engine=engine)

Documentation

The whole public API of this package is described here and follows semantic versioning rules. Everyting outside of this readme are private API and could be changed without any notification on any new version.

Storage

Package implements Tabular Storage interface (see full documentation on the link):

This driver provides an additional API:

Storage(engine, dbschema=None, prefix='', reflect_only=None, autoincrement=None)

• engine (object) - sqlalchemy engine
• dbschema (str) - name of database schema
• prefix (str) - prefix for all buckets
• reflect_only (callable) - a boolean predicate to filter the list of table names when reflecting
• autoincrement (str/dict) - add autoincrement column at the beginning.
  • if a string it's an autoincrement column name
  • if a dict it's an autoincrements mapping with column names indexed by bucket names, for example, {'bucket1': 'id', 'bucket2': 'other_id}

storage.create(..., indexes_fields=None)

• indexes_fields (str[]) - list of tuples containing field names, or list of such lists

storage.write(..., keyed=False, as_generator=False, update_keys=None)

• keyed (bool) - accept keyed rows
• as_generator (bool) - returns generator to provide writing control to the client
• update_keys (str[]) - update instead of inserting if key values match existent rows
• buffer_size (int=1000) - maximum number of rows to try and write to the db in one batch
• use_bloom_filter (bool=True) - should we use a bloom filter to optimize DB update performance (in exchange for some setup time)

Contributing

The project follows the Open Knowledge International coding standards.

Recommended way to get started is to create and activate a project virtual environment. To install package and development dependencies into active environment:

$ make install

To run tests with linting and coverage:

$ make test

For linting pylama configured in pylama.ini is used. On this stage it's already installed into your environment and could be used separately with more fine-grained control as described in documentation - https://pylama.readthedocs.io/en/latest/.

For example to sort results by error type:

$ pylama --sort <path>

For testing tox configured in tox.ini is used. It's already installed into your environment and could be used separately with more fine-grained control as described in documentation - https://testrun.org/tox/latest/.

For example to check subset of tests against Python 2 environment with increased verbosity. All positional arguments and options after -- will be passed to py.test:

tox -e py27 -- -v tests/<path>

Under the hood tox uses pytest configured in pytest.ini, coverage and mock packages. This packages are available only in tox envionments.

Changelog

Here described only breaking and the most important changes. The full changelog and documentation for all released versions could be found in nicely formatted commit history.

v1.3

• Implemented constraints loading to a database

v1.2

• Add option to configure buffer size, bloom filter use (#77)

v1.1

• Added support for the autoincrement parameter to be a mapping
• Fixed autoincrement support for SQLite and MySQL

v1.0

• Initial driver implementation.