Loading django/db/backends/__init__.py +3 −0 Original line number Diff line number Diff line Loading @@ -432,6 +432,9 @@ class BaseDatabaseFeatures(object): # What's the maximum length for index names? max_index_name_length = 63 # Does it support foreign keys? supports_foreign_keys = True def __init__(self, connection): self.connection = connection Loading django/db/backends/schema.py +2 −2 Original line number Diff line number Diff line Loading @@ -187,7 +187,7 @@ class BaseDatabaseSchemaEditor(object): } ) # FK if field.rel: if field.rel and self.connection.features.supports_foreign_keys: to_table = field.rel.to._meta.db_table to_column = field.rel.to._meta.get_field(field.rel.field_name).column self.deferred_sql.append( Loading Loading @@ -311,7 +311,7 @@ class BaseDatabaseSchemaEditor(object): } } # Add any FK constraints later if field.rel: if field.rel and self.connection.features.supports_foreign_keys: to_table = field.rel.to._meta.db_table to_column = field.rel.to._meta.get_field(field.rel.field_name).column self.deferred_sql.append( Loading django/db/backends/sqlite3/base.py +1 −0 Original line number Diff line number Diff line Loading @@ -96,6 +96,7 @@ class DatabaseFeatures(BaseDatabaseFeatures): supports_mixed_date_datetime_comparisons = False has_bulk_insert = True can_combine_inserts_with_and_without_auto_increment_pk = False supports_foreign_keys = False @cached_property def supports_stddev(self): Loading django/db/backends/sqlite3/introspection.py +35 −1 Original line number Diff line number Diff line Loading @@ -154,7 +154,7 @@ class DatabaseIntrospection(BaseDatabaseIntrospection): if len(info) != 1: continue name = info[0][2] # seqno, cid, name indexes[name] = {'primary_key': False, indexes[name] = {'primary_key': indexes.get(name, {}).get("primary_key", False), 'unique': unique} return indexes Loading Loading @@ -182,3 +182,37 @@ class DatabaseIntrospection(BaseDatabaseIntrospection): 'null_ok': not field[3], 'pk': field[5] # undocumented } for field in cursor.fetchall()] def get_constraints(self, cursor, table_name): """ Retrieves any constraints or keys (unique, pk, fk, check, index) across one or more columns. """ constraints = {} # Get the index info cursor.execute("PRAGMA index_list(%s)" % self.connection.ops.quote_name(table_name)) for number, index, unique in cursor.fetchall(): # Get the index info for that index cursor.execute('PRAGMA index_info(%s)' % self.connection.ops.quote_name(index)) for index_rank, column_rank, column in cursor.fetchall(): if index not in constraints: constraints[index] = { "columns": set(), "primary_key": False, "unique": bool(unique), "foreign_key": False, "check": False, "index": True, } constraints[index]['columns'].add(column) # Get the PK pk_column = self.get_primary_key_column(cursor, table_name) if pk_column: constraints["__primary__"] = { "columns": set([pk_column]), "primary_key": True, "unique": False, # It's not actually a unique constraint "foreign_key": False, "check": False, "index": False, } return constraints django/db/backends/sqlite3/schema.py +110 −0 Original line number Diff line number Diff line from django.db.backends.schema import BaseDatabaseSchemaEditor from django.db.models.loading import cache from django.db.models.fields.related import ManyToManyField class DatabaseSchemaEditor(BaseDatabaseSchemaEditor): sql_delete_table = "DROP TABLE %(table)s" def _remake_table(self, model, create_fields=[], delete_fields=[], alter_fields=[], rename_fields=[], override_uniques=None): "Shortcut to transform a model from old_model into new_model" # Work out the new fields dict / mapping body = dict((f.name, f) for f in model._meta.local_fields) mapping = dict((f.column, f.column) for f in model._meta.local_fields) # If any of the new or altered fields is introducing a new PK, # remove the old one restore_pk_field = None if any(f.primary_key for f in create_fields) or any(n.primary_key for o, n in alter_fields): for name, field in list(body.items()): if field.primary_key: field.primary_key = False restore_pk_field = field if field.auto_created: del body[name] del mapping[field.column] # Add in any created fields for field in create_fields: body[field.name] = field # Add in any altered fields for (old_field, new_field) in alter_fields: del body[old_field.name] del mapping[old_field.column] body[new_field.name] = new_field mapping[new_field.column] = old_field.column # Remove any deleted fields for field in delete_fields: del body[field.name] del mapping[field.column] # Construct a new model for the new state meta_contents = { 'app_label': model._meta.app_label, 'db_table': model._meta.db_table + "__new", 'unique_together': model._meta.unique_together if override_uniques is None else override_uniques, } meta = type("Meta", tuple(), meta_contents) body['Meta'] = meta body['__module__'] = "__fake__" with cache.temporary_state(): del cache.app_models[model._meta.app_label][model._meta.object_name.lower()] temp_model = type(model._meta.object_name, model.__bases__, body) # Create a new table with that format self.create_model(temp_model) # Copy data from the old table field_maps = list(mapping.items()) self.execute("INSERT INTO %s (%s) SELECT %s FROM %s;" % ( self.quote_name(temp_model._meta.db_table), ', '.join([x for x, y in field_maps]), ', '.join([y for x, y in field_maps]), self.quote_name(model._meta.db_table), )) # Delete the old table self.delete_model(model) # Rename the new to the old self.alter_db_table(model, temp_model._meta.db_table, model._meta.db_table) # Run deferred SQL on correct table for sql in self.deferred_sql: self.execute(sql.replace(temp_model._meta.db_table, model._meta.db_table)) self.deferred_sql = [] # Fix any PK-removed field if restore_pk_field: restore_pk_field.primary_key = True def create_field(self, model, field): """ Creates a field on a model. Usually involves adding a column, but may involve adding a table instead (for M2M fields) """ # Special-case implicit M2M tables if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created: return self.create_model(field.rel.through) # Detect bad field combinations if (not field.null and (not field.has_default() or field.get_default() is None) and not field.empty_strings_allowed): 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): """ Removes a field from a model. Usually involves deleting a column, but for M2Ms may involve deleting a table. """ # Special-case implicit M2M tables if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created: return self.delete_model(field.rel.through) # For everything else, remake. self._remake_table(model, delete_fields=[field]) def alter_field(self, model, old_field, new_field, strict=False): # Ensure this field is even column-based old_type = old_field.db_type(connection=self.connection) new_type = self._type_for_alter(new_field) if old_type is None and new_type is None: # TODO: Handle M2M fields being repointed return elif old_type is None or new_type is None: raise ValueError("Cannot alter field %s into %s - they are not compatible types" % ( old_field, new_field, )) # Alter by remaking table self._remake_table(model, alter_fields=[(old_field, new_field)]) def alter_unique_together(self, model, old_unique_together, new_unique_together): self._remake_table(model, override_uniques=new_unique_together) Loading
django/db/backends/__init__.py +3 −0 Original line number Diff line number Diff line Loading @@ -432,6 +432,9 @@ class BaseDatabaseFeatures(object): # What's the maximum length for index names? max_index_name_length = 63 # Does it support foreign keys? supports_foreign_keys = True def __init__(self, connection): self.connection = connection Loading
django/db/backends/schema.py +2 −2 Original line number Diff line number Diff line Loading @@ -187,7 +187,7 @@ class BaseDatabaseSchemaEditor(object): } ) # FK if field.rel: if field.rel and self.connection.features.supports_foreign_keys: to_table = field.rel.to._meta.db_table to_column = field.rel.to._meta.get_field(field.rel.field_name).column self.deferred_sql.append( Loading Loading @@ -311,7 +311,7 @@ class BaseDatabaseSchemaEditor(object): } } # Add any FK constraints later if field.rel: if field.rel and self.connection.features.supports_foreign_keys: to_table = field.rel.to._meta.db_table to_column = field.rel.to._meta.get_field(field.rel.field_name).column self.deferred_sql.append( Loading
django/db/backends/sqlite3/base.py +1 −0 Original line number Diff line number Diff line Loading @@ -96,6 +96,7 @@ class DatabaseFeatures(BaseDatabaseFeatures): supports_mixed_date_datetime_comparisons = False has_bulk_insert = True can_combine_inserts_with_and_without_auto_increment_pk = False supports_foreign_keys = False @cached_property def supports_stddev(self): Loading
django/db/backends/sqlite3/introspection.py +35 −1 Original line number Diff line number Diff line Loading @@ -154,7 +154,7 @@ class DatabaseIntrospection(BaseDatabaseIntrospection): if len(info) != 1: continue name = info[0][2] # seqno, cid, name indexes[name] = {'primary_key': False, indexes[name] = {'primary_key': indexes.get(name, {}).get("primary_key", False), 'unique': unique} return indexes Loading Loading @@ -182,3 +182,37 @@ class DatabaseIntrospection(BaseDatabaseIntrospection): 'null_ok': not field[3], 'pk': field[5] # undocumented } for field in cursor.fetchall()] def get_constraints(self, cursor, table_name): """ Retrieves any constraints or keys (unique, pk, fk, check, index) across one or more columns. """ constraints = {} # Get the index info cursor.execute("PRAGMA index_list(%s)" % self.connection.ops.quote_name(table_name)) for number, index, unique in cursor.fetchall(): # Get the index info for that index cursor.execute('PRAGMA index_info(%s)' % self.connection.ops.quote_name(index)) for index_rank, column_rank, column in cursor.fetchall(): if index not in constraints: constraints[index] = { "columns": set(), "primary_key": False, "unique": bool(unique), "foreign_key": False, "check": False, "index": True, } constraints[index]['columns'].add(column) # Get the PK pk_column = self.get_primary_key_column(cursor, table_name) if pk_column: constraints["__primary__"] = { "columns": set([pk_column]), "primary_key": True, "unique": False, # It's not actually a unique constraint "foreign_key": False, "check": False, "index": False, } return constraints
django/db/backends/sqlite3/schema.py +110 −0 Original line number Diff line number Diff line from django.db.backends.schema import BaseDatabaseSchemaEditor from django.db.models.loading import cache from django.db.models.fields.related import ManyToManyField class DatabaseSchemaEditor(BaseDatabaseSchemaEditor): sql_delete_table = "DROP TABLE %(table)s" def _remake_table(self, model, create_fields=[], delete_fields=[], alter_fields=[], rename_fields=[], override_uniques=None): "Shortcut to transform a model from old_model into new_model" # Work out the new fields dict / mapping body = dict((f.name, f) for f in model._meta.local_fields) mapping = dict((f.column, f.column) for f in model._meta.local_fields) # If any of the new or altered fields is introducing a new PK, # remove the old one restore_pk_field = None if any(f.primary_key for f in create_fields) or any(n.primary_key for o, n in alter_fields): for name, field in list(body.items()): if field.primary_key: field.primary_key = False restore_pk_field = field if field.auto_created: del body[name] del mapping[field.column] # Add in any created fields for field in create_fields: body[field.name] = field # Add in any altered fields for (old_field, new_field) in alter_fields: del body[old_field.name] del mapping[old_field.column] body[new_field.name] = new_field mapping[new_field.column] = old_field.column # Remove any deleted fields for field in delete_fields: del body[field.name] del mapping[field.column] # Construct a new model for the new state meta_contents = { 'app_label': model._meta.app_label, 'db_table': model._meta.db_table + "__new", 'unique_together': model._meta.unique_together if override_uniques is None else override_uniques, } meta = type("Meta", tuple(), meta_contents) body['Meta'] = meta body['__module__'] = "__fake__" with cache.temporary_state(): del cache.app_models[model._meta.app_label][model._meta.object_name.lower()] temp_model = type(model._meta.object_name, model.__bases__, body) # Create a new table with that format self.create_model(temp_model) # Copy data from the old table field_maps = list(mapping.items()) self.execute("INSERT INTO %s (%s) SELECT %s FROM %s;" % ( self.quote_name(temp_model._meta.db_table), ', '.join([x for x, y in field_maps]), ', '.join([y for x, y in field_maps]), self.quote_name(model._meta.db_table), )) # Delete the old table self.delete_model(model) # Rename the new to the old self.alter_db_table(model, temp_model._meta.db_table, model._meta.db_table) # Run deferred SQL on correct table for sql in self.deferred_sql: self.execute(sql.replace(temp_model._meta.db_table, model._meta.db_table)) self.deferred_sql = [] # Fix any PK-removed field if restore_pk_field: restore_pk_field.primary_key = True def create_field(self, model, field): """ Creates a field on a model. Usually involves adding a column, but may involve adding a table instead (for M2M fields) """ # Special-case implicit M2M tables if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created: return self.create_model(field.rel.through) # Detect bad field combinations if (not field.null and (not field.has_default() or field.get_default() is None) and not field.empty_strings_allowed): 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): """ Removes a field from a model. Usually involves deleting a column, but for M2Ms may involve deleting a table. """ # Special-case implicit M2M tables if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created: return self.delete_model(field.rel.through) # For everything else, remake. self._remake_table(model, delete_fields=[field]) def alter_field(self, model, old_field, new_field, strict=False): # Ensure this field is even column-based old_type = old_field.db_type(connection=self.connection) new_type = self._type_for_alter(new_field) if old_type is None and new_type is None: # TODO: Handle M2M fields being repointed return elif old_type is None or new_type is None: raise ValueError("Cannot alter field %s into %s - they are not compatible types" % ( old_field, new_field, )) # Alter by remaking table self._remake_table(model, alter_fields=[(old_field, new_field)]) def alter_unique_together(self, model, old_unique_together, new_unique_together): self._remake_table(model, override_uniques=new_unique_together)
