Migrate Alembic to Alchemical format

alembic.ini

@@ -1,18 +1,29 @@
-# A generic, single database configuration.
+# a multi-database configuration.
 
 [alembic]
+# this must be configured to point to the Alchemical database instance
+# there are two components separated by a colon:
+# the left part is the import path to the module containing the database instance
+# the right part is the name of the database instance, typically 'db'
+alchemical_db = models:db
+
 # path to migration scripts
 script_location = migrations
 
-# template used to generate migration files
-# file_template = %%(rev)s_%%(slug)s
+# template used to generate migration file names; The default value is %%(rev)s_%%(slug)s
+# Uncomment the line below if you want the files to be prepended with date and time
+# see https://alembic.sqlalchemy.org/en/latest/tutorial.html#editing-the-ini-file
+# for all available tokens
+# file_template = %%(year)d_%%(month).2d_%%(day).2d_%%(hour).2d%%(minute).2d-%%(rev)s_%%(slug)s
 
 # sys.path path, will be prepended to sys.path if present.
 # defaults to the current working directory.
-prepend_sys_path = .
+prepend_sys_path = app
 
-# timezone to use when rendering the date
-# within the migration file as well as the filename.
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the python-dateutil library that can be
+# installed by adding `alembic[tz]` to the pip requirements
 # string value is passed to dateutil.tz.gettz()
 # leave blank for localtime
 # timezone =
@@ -30,20 +41,26 @@ prepend_sys_path = .
 # versions/ directory
 # sourceless = false
 
-# version location specification; this defaults
+# version location specification; This defaults
 # to migrations/versions.  When using multiple version
-# directories, initial revisions must be specified with --version-path
-# version_locations = %(here)s/bar %(here)s/bat migrations/versions
+# directories, initial revisions must be specified with --version-path.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:migrations/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
 
 # the output encoding used when revision files
 # are written from script.py.mako
 # output_encoding = utf-8
 
-sqlalchemy.url = SET
-# sqlalchemy.url = mysql+mysqldb://musicmuster:musicmuster@localhost/musicmuster_prod
-# sqlalchemy.url = mysql+mysqldb://dev_musicmuster:dev_musicmuster@localhost/dev_musicmuster
-# sqlalchemy.url = mysql+mysqldb://dev_musicmuster:dev_musicmuster@localhost/dev_musicmuster_carts
-
 [post_write_hooks]
 # post_write_hooks defines scripts or Python functions that are run
 # on newly generated revision scripts.  See the documentation for further
@@ -53,7 +70,7 @@ sqlalchemy.url = SET
 # hooks = black
 # black.type = console_scripts
 # black.entrypoint = black
-# black.options=-l 79
+# black.options = -l 79 REVISION_SCRIPT_FILENAME
 
 # Logging configuration
 [loggers]

migrations/README

@@ -1 +1 @@
-Generic single-database configuration.
+Alembic configuration for Alchemical

migrations/env.py

@@ -1,84 +1,27 @@
-import sys
-import os
-
-from logging.config import fileConfig
-
-from sqlalchemy import engine_from_config
-from sqlalchemy import pool
-
+from importlib import import_module
 from alembic import context
+from alchemical.alembic.env import run_migrations
 
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.
 config = context.config
 
-# Interpret the config file for Python logging.
-# This line sets up loggers basically.
-fileConfig(config.config_file_name)
-
-# add your model's MetaData object here
-# for 'autogenerate' support
-# from myapp import mymodel
-# target_metadata = mymodel.Base.metadata
-# https://stackoverflow.com/questions/32032940/how-to-import-the-own-model-into-myproject-alembic-env-py
-path = os.path.dirname(os.path.dirname(__file__))
-sys.path.insert(0, path)
-sys.path.insert(0, os.path.join(path, "app"))
-from app.models import Base
-target_metadata = Base.metadata
-# other values from the config, defined by the needs of env.py,
-# can be acquired:
-# my_important_option = config.get_main_option("my_important_option")
-# ... etc.
-
-
-def run_migrations_offline():
-    """Run migrations in 'offline' mode.
-
-    This configures the context with just a URL
-    and not an Engine, though an Engine is acceptable
-    here as well.  By skipping the Engine creation
-    we don't even need a DBAPI to be available.
-
-    Calls to context.execute() here emit the given string to the
-    script output.
-
-    """
-    url = config.get_main_option("sqlalchemy.url")
-    context.configure(
-        url=url,
-        target_metadata=target_metadata,
-        literal_binds=True,
-        dialect_opts={"paramstyle": "named"},
+# import the application's Alchemical instance
+try:
+    import_mod, db_name = config.get_main_option('alchemical_db', '').split(
+        ':')
+    db = getattr(import_module(import_mod), db_name)
+except (ModuleNotFoundError, AttributeError):
+    raise ValueError(
+        'Could not import the Alchemical database instance. '
+        'Ensure that the alchemical_db setting in alembic.ini is correct.'
     )
 
-    with context.begin_transaction():
-        context.run_migrations()
-
-
-def run_migrations_online():
-    """Run migrations in 'online' mode.
-
-    In this scenario we need to create an Engine
-    and associate a connection with the context.
-
-    """
-    connectable = engine_from_config(
-        config.get_section(config.config_ini_section),
-        prefix="sqlalchemy.",
-        poolclass=pool.NullPool,
-    )
-
-    with connectable.connect() as connection:
-        context.configure(
-            connection=connection, target_metadata=target_metadata
-        )
-
-        with context.begin_transaction():
-            context.run_migrations()
-
-
-if context.is_offline_mode():
-    run_migrations_offline()
-else:
-    run_migrations_online()
+# run the migration engine
+# The dictionary provided as second argument includes options to pass to the
+# Alembic context. For details on what other options are available, see
+# https://alembic.sqlalchemy.org/en/latest/autogenerate.html
+run_migrations(db, {
+    'render_as_batch': True,
+    'compare_type': True,
+})

migrations/versions/2caa3d37f211_add_tracks_intro_column.py

@@ -0,0 +1,110 @@
+"""add Tracks.intro column
+
+Revision ID: 2caa3d37f211
+Revises: 5bb2c572e1e5
+Create Date: 2024-05-07 20:06:00.845979
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import mysql
+
+# revision identifiers, used by Alembic.
+revision = '2caa3d37f211'
+down_revision = '5bb2c572e1e5'
+branch_labels = None
+depends_on = None
+
+
+def upgrade(engine_name: str) -> None:
+    globals()["upgrade_%s" % engine_name]()
+
+
+def downgrade(engine_name: str) -> None:
+    globals()["downgrade_%s" % engine_name]()
+
+
+
+
+
+def upgrade_() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('carts', schema=None) as batch_op:
+        batch_op.alter_column('name',
+               existing_type=mysql.VARCHAR(length=256),
+               nullable=False)
+
+    with op.batch_alter_table('notecolours', schema=None) as batch_op:
+        batch_op.alter_column('substring',
+               existing_type=mysql.VARCHAR(length=256),
+               nullable=False)
+        batch_op.alter_column('colour',
+               existing_type=mysql.VARCHAR(length=21),
+               nullable=False)
+        batch_op.alter_column('enabled',
+               existing_type=mysql.TINYINT(display_width=1),
+               nullable=False)
+        batch_op.alter_column('is_regex',
+               existing_type=mysql.TINYINT(display_width=1),
+               nullable=False)
+        batch_op.alter_column('is_casesensitive',
+               existing_type=mysql.TINYINT(display_width=1),
+               nullable=False)
+
+    with op.batch_alter_table('playdates', schema=None) as batch_op:
+        batch_op.alter_column('lastplayed',
+               existing_type=mysql.DATETIME(),
+               nullable=False)
+        batch_op.alter_column('track_id',
+               existing_type=mysql.INTEGER(display_width=11),
+               nullable=False)
+
+    with op.batch_alter_table('playlists', schema=None) as batch_op:
+        batch_op.drop_index('tab')
+
+    with op.batch_alter_table('tracks', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('intro', sa.Integer(), nullable=True))
+
+    # ### end Alembic commands ###
+
+
+def downgrade_() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('tracks', schema=None) as batch_op:
+        batch_op.drop_column('intro')
+
+    with op.batch_alter_table('playlists', schema=None) as batch_op:
+        batch_op.create_index('tab', ['tab'], unique=True)
+
+    with op.batch_alter_table('playdates', schema=None) as batch_op:
+        batch_op.alter_column('track_id',
+               existing_type=mysql.INTEGER(display_width=11),
+               nullable=True)
+        batch_op.alter_column('lastplayed',
+               existing_type=mysql.DATETIME(),
+               nullable=True)
+
+    with op.batch_alter_table('notecolours', schema=None) as batch_op:
+        batch_op.alter_column('is_casesensitive',
+               existing_type=mysql.TINYINT(display_width=1),
+               nullable=True)
+        batch_op.alter_column('is_regex',
+               existing_type=mysql.TINYINT(display_width=1),
+               nullable=True)
+        batch_op.alter_column('enabled',
+               existing_type=mysql.TINYINT(display_width=1),
+               nullable=True)
+        batch_op.alter_column('colour',
+               existing_type=mysql.VARCHAR(length=21),
+               nullable=True)
+        batch_op.alter_column('substring',
+               existing_type=mysql.VARCHAR(length=256),
+               nullable=True)
+
+    with op.batch_alter_table('carts', schema=None) as batch_op:
+        batch_op.alter_column('name',
+               existing_type=mysql.VARCHAR(length=256),
+               nullable=True)
+
+    # ### end Alembic commands ###
+