Commit d0ecefc2 authored by Andrew Godwin's avatar Andrew Godwin
Browse files

Start adding operations that work and tests for them

parent 264f8650

django/db/backends/schema.py

+2 −2
Original line number Diff line number Diff line
@@ -272,7 +272,7 @@ class BaseDatabaseSchemaEditor(object): 
            "new_tablespace": self.quote_name(new_db_tablespace),

        })



    def create_field(self, model, field, keep_default=False):

    def add_field(self, model, field, keep_default=False):

        """

        Creates a field on a model.

        Usually involves adding a column, but may involve adding a
@@ -325,7 +325,7 @@ class BaseDatabaseSchemaEditor(object): 
                }

            )



    def delete_field(self, model, field):

    def remove_field(self, model, field):

        """

        Removes a field from a model. Usually involves deleting a column,

        but for M2Ms may involve deleting a table.

django/db/backends/sqlite3/schema.py

+2 −2
Original line number Diff line number Diff line
@@ -73,7 +73,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor): 
        if restore_pk_field:

            restore_pk_field.primary_key = True



    def create_field(self, model, field):

    def add_field(self, model, field):

        """

        Creates a field on a model.

        Usually involves adding a column, but may involve adding a
@@ -89,7 +89,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor): 
            raise ValueError("You cannot add a null=False column without a default value on SQLite.")

        self._remake_table(model, create_fields=[field])



    def delete_field(self, model, field):

    def remove_field(self, model, field):

        """

        Removes a field from a model. Usually involves deleting a column,

        but for M2Ms may involve deleting a table.

django/db/migrations/__init__.py

+1 −0
Original line number Diff line number Diff line 
from .migration import Migration

from .operations import *

django/db/migrations/graph.py

+15 −2
Original line number Diff line number Diff line 
from django.utils.datastructures import SortedSet

from django.db.migrations.state import ProjectState





class MigrationGraph(object):
@@ -33,8 +34,10 @@ class MigrationGraph(object): 
        self.nodes[node] = implementation



    def add_dependency(self, child, parent):

        self.nodes[child] = None

        self.nodes[parent] = None

        if child not in self.nodes:

            raise KeyError("Dependency references nonexistent child node %r" % (child,))

        if parent not in self.nodes:

            raise KeyError("Dependency references nonexistent parent node %r" % (parent,))

        self.dependencies.setdefault(child, set()).add(parent)

        self.dependents.setdefault(parent, set()).add(child)
@@ -117,6 +120,16 @@ class MigrationGraph(object): 
    def __str__(self):

        return "Graph: %s nodes, %s edges" % (len(self.nodes), sum(len(x) for x in self.dependencies.values()))



    def project_state(self, node):

        """

        Given a migration node, returns a complete ProjectState for it.

        """

        plan = self.forwards_plan(node)

        project_state = ProjectState()

        for node in plan:

            project_state = self.nodes[node].mutate_state(project_state)

        return project_state





class CircularDependencyError(Exception):

    """

django/db/migrations/loader.py

+5 −2
Original line number Diff line number Diff line 
import os

from django.utils.importlib import import_module

from django.utils.functional import cached_property

from django.db.models.loading import cache

from django.db.migrations.recorder import MigrationRecorder

from django.db.migrations.graph import MigrationGraph
@@ -64,9 +65,10 @@ class MigrationLoader(object): 
                migration_module = import_module("%s.%s" % (module_name, migration_name))

                if not hasattr(migration_module, "Migration"):

                    raise BadMigrationError("Migration %s in app %s has no Migration class" % (migration_name, app_label))

                self.disk_migrations[app_label, migration_name] = migration_module.Migration

                self.disk_migrations[app_label, migration_name] = migration_module.Migration(migration_name, app_label)



    def build_graph(self):

    @cached_property

    def graph(self):

        """

        Builds a migration dependency graph using both the disk and database.

        """
@@ -116,6 +118,7 @@ class MigrationLoader(object): 
        graph = MigrationGraph()

        for key, migration in normal.items():

            graph.add_node(key, migration)

        for key, migration in normal.items():

            for parent in migration.dependencies:

                graph.add_dependency(key, parent)

        return graph