Metadata-Version: 1.1
Name: alembic
Version: 0.9.6
Summary: A database migration tool for SQLAlchemy.
Home-page: http://bitbucket.org/zzzeek/alembic
Author: Mike Bayer
Author-email: mike@zzzcomputing.com
License: MIT
Description: Alembic is a database migrations tool written by the author
        of `SQLAlchemy <http://www.sqlalchemy.org>`_.  A migrations tool
        offers the following functionality:
        
        * Can emit ALTER statements to a database in order to change
          the structure of tables and other constructs
        * Provides a system whereby "migration scripts" may be constructed;
          each script indicates a particular series of steps that can "upgrade" a
          target database to a new version, and optionally a series of steps that can
          "downgrade" similarly, doing the same steps in reverse.
        * Allows the scripts to execute in some sequential manner.
        
        The goals of Alembic are:
        
        * Very open ended and transparent configuration and operation.   A new
          Alembic environment is generated from a set of templates which is selected
          among a set of options when setup first occurs. The templates then deposit a
          series of scripts that define fully how database connectivity is established
          and how migration scripts are invoked; the migration scripts themselves are
          generated from a template within that series of scripts. The scripts can
          then be further customized to define exactly how databases will be
          interacted with and what structure new migration files should take.
        * Full support for transactional DDL.   The default scripts ensure that all
          migrations occur within a transaction - for those databases which support
          this (Postgresql, Microsoft SQL Server), migrations can be tested with no
          need to manually undo changes upon failure.
        * Minimalist script construction.  Basic operations like renaming
          tables/columns, adding/removing columns, changing column attributes can be
          performed through one line commands like alter_column(), rename_table(),
          add_constraint(). There is no need to recreate full SQLAlchemy Table
          structures for simple operations like these - the functions themselves
          generate minimalist schema structures behind the scenes to achieve the given
          DDL sequence.
        * "auto generation" of migrations. While real world migrations are far more
          complex than what can be automatically determined, Alembic can still
          eliminate the initial grunt work in generating new migration directives
          from an altered schema.  The ``--autogenerate`` feature will inspect the
          current status of a database using SQLAlchemy's schema inspection
          capabilities, compare it to the current state of the database model as
          specified in Python, and generate a series of "candidate" migrations,
          rendering them into a new migration script as Python directives. The
          developer then edits the new file, adding additional directives and data
          migrations as needed, to produce a finished migration. Table and column
          level changes can be detected, with constraints and indexes to follow as
          well.
        * Full support for migrations generated as SQL scripts.   Those of us who
          work in corporate environments know that direct access to DDL commands on a
          production database is a rare privilege, and DBAs want textual SQL scripts.
          Alembic's usage model and commands are oriented towards being able to run a
          series of migrations into a textual output file as easily as it runs them
          directly to a database. Care must be taken in this mode to not invoke other
          operations that rely upon in-memory SELECTs of rows - Alembic tries to
          provide helper constructs like bulk_insert() to help with data-oriented
          operations that are compatible with script-based DDL.
        * Non-linear, dependency-graph versioning.   Scripts are given UUID
          identifiers similarly to a DVCS, and the linkage of one script to the next
          is achieved via human-editable markers within the scripts themselves.
          The structure of a set of migration files is considered as a
          directed-acyclic graph, meaning any migration file can be dependent
          on any other arbitrary set of migration files, or none at
          all.  Through this open-ended system, migration files can be organized
          into branches, multiple roots, and mergepoints, without restriction.
          Commands are provided to produce new branches, roots, and merges of
          branches automatically.
        * Provide a library of ALTER constructs that can be used by any SQLAlchemy
          application. The DDL constructs build upon SQLAlchemy's own DDLElement base
          and can be used standalone by any application or script.
        * At long last, bring SQLite and its inablity to ALTER things into the fold,
          but in such a way that SQLite's very special workflow needs are accommodated
          in an explicit way that makes the most of a bad situation, through the
          concept of a "batch" migration, where multiple changes to a table can
          be batched together to form a series of instructions for a single, subsequent
          "move-and-copy" workflow.   You can even use "move-and-copy" workflow for
          other databases, if you want to recreate a table in the background
          on a busy system.
        
        Documentation and status of Alembic is at http://alembic.zzzcomputing.com/
        
        
Keywords: SQLAlchemy migrations
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Environment :: Console
Classifier: Intended Audience :: Developers
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Classifier: Topic :: Database :: Front-Ends
