API Documentation

class miggy.migrator.State(data: dict[str, type[Model]] | None = None)

Current state containing historical models that match the operation’s place in the project history. This is a dict-like class that stores data in the format model_name: model_class. The model_name is case-insensitive.

Example:

User = state["user"]
User.get(id=1)

class miggy.migrator.SchemaMigrator(database)

Extended playhouse.migrate.SchemaMigrator from peewee

sql(sql, params: tuple[Any, ...] | None = None)

Execute raw SQL.

rename_index(old_name: str, new_name: str)

Change index name

create_table(model: type[Model], safe: bool = False) → Callable

Create table from model class

drop_table(model: type[Model], safe: bool = False) → Callable

Drop model table

Migrate operations

class miggy.migrator.MigrateOperation

Base class for a migrate operation

state_forwards(state: State) → None

Take the state from the previous migration, and mutate it so that it matches what this migration would perform.

database_forwards(schema_migrator: SchemaMigrator, from_state: State, to_state: State) → list[Operation] | list[Callable]

Perform the mutation on the database schema in the normal (forwards) direction. The method MUST NOT mutate provided states.

class miggy.migrator.RunPython(func: Callable[[SchemaMigrator, State], None])

Allows to run custom Python code. func should be callable object that accept two arguments; the first is an instance of SchemaMigrator and the second is an instance of State

Example:

def save_user(schema_migrator: SchemaMigrator, current_state: State):
    User = current_state["user"]
    User(
        first_name="First",
        last_name="Last",
    ).save()

migrator.add_operaion(RunPython(save_user))

class miggy.migrator.RunSql(sql: str, params: tuple[Any, ...] | None = None)

Allows running of arbitrary SQL on the database - useful for more advanced features of database backends that Miggy doesn’t support directly.

Example:

migrator.add_operation(
    RunSql(
        'INSERT INTO "user" ("first_name", "last_name") VALUES (%s, %s)',
        (
            "First",
            "Last",
        ),
    )
)

class miggy.migrator.CreateModel(model: type[Model])

Creates a new model in the State and a corresponding table in the database to match it.

class miggy.migrator.RemoveModel(model_name: str)

Deletes the model from the State and its table from the database.

class miggy.migrator.AddIndex(model_name: str, *fields: str, name: str, unique: bool = False, where: SQL | None = None, safe: bool = False, concurrently: bool = False)

Creates an index in the database table for the model with model_name. The index will be saved in Model._meta.indexes_state dict

class miggy.migrator.DropIndex(model_name: str, name: str)

Removes the index named name from the model with model_name.

class miggy.migrator.RenameTable(model_name: str, new_table_name: str)

Renames the model from the old name to a new one. It also renames all single-column indexes, if they exist.

Warning:

This operation does not rename indexes created via the Meta class or the add_index() method. You should explicitly specify index names if you plan to use this operation. Otherwise, you will be prompted to recreate the indexes with a new name in the next migration.

class miggy.migrator.AddFields(model_name: str, **fields: Field)

Adds fields to a model.

class miggy.migrator.ChangeFields(model_name: str, **fields: Field)

Change fields to a model.

class miggy.migrator.RemoveFields(model_name: str, *names: str, cascade: bool = False)

Removes fields from a model

class miggy.migrator.RenameField(model_name: str, old_name: str, new_name: str)

Changes a field’s name (and, unless column_name is set, its column name). It also renames a single-column indexe, if it exists.

Warning:

This operation does not rename indexes created via the Meta class or the add_index() method. You should explicitly specify index names if you plan to use this operation. Otherwise, you will be prompted to recreate the index with a new name in the next migration.

Migrator

class miggy.migrator.Migrator(database, schema=None)

A class that provides shortcuts for adding migration operations.

add_operation(op: MigrateOperation) → None

Adds a migrate operation

python(func: Callable[[SchemaMigrator, State], None])

A shortcut for adding a RunPython operation.

sql(sql: str, params: tuple[Any, ...] | None = None) → None

A shortcut for adding a RunSql operation.

create_model(model: type[Model]) → type[Model]

A shortcut for adding a CreateModel operation.

remove_model(model_name: str) → None

A shortcut for adding a RemoveModel operation.

add_fields(model_name: str, **fields: Any) → None

A shortcut for adding a AddFields operation.

change_fields(model_name: str, **fields: Field) → None

A shortcut for adding a ChangeFields operation.

remove_fields(model_name: str, *names: str, cascade: bool = False) → None

A shortcut for adding a RemoveFields operation.

rename_field(model_name: str, old_name: str, new_name: str) → None

A shortcut for adding a RenameField operation.

rename_table(model_name: str, new_table_name: str) → None

A shortcut for adding a RenameTable operation.

add_index(model_name: str, *fields: str, name: str, unique: bool = False, where: SQL | None = None, safe: bool = False, concurrently: bool = False) → None

A shortcut for adding a AddIndex operation.

drop_index(model_name: str, name: str) → None

A shortcut for adding a DropIndex operation.