From dfadbdac6a63dce3304dff1977b5b0a15dc2d7b5 Mon Sep 17 00:00:00 2001 From: Anssi Kääriäinen Date: Mon, 11 Aug 2014 12:47:37 +0300 Subject: Fixed #16426 -- deletion of 1000+ objects with relations on SQLite SQLite doesn't work with more than 1000 parameters in a single query. The deletion code could generate queries that try to get related objects for more than 1000 objects thus breaking the limit. Django now splits the related object fetching into batches with at most 1000 parameters. The tests and patch include some work done by Trac alias NiGhTTraX in ticket #21205. --- django/db/models/deletion.py | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) (limited to 'django') diff --git a/django/db/models/deletion.py b/django/db/models/deletion.py index e3c38a03cc..dffdf808d1 100644 --- a/django/db/models/deletion.py +++ b/django/db/models/deletion.py @@ -144,6 +144,18 @@ class Collector(object): return False return True + def get_del_batches(self, objs, field): + """ + Returns the objs in suitably sized batches for the used connection. + """ + conn_batch_size = max( + connections[self.using].ops.bulk_batch_size([field.name], objs), 1) + if len(objs) > conn_batch_size: + return [objs[i:i + conn_batch_size] + for i in range(0, len(objs), conn_batch_size)] + else: + return [objs] + def collect(self, objs, source=None, nullable=False, collect_related=True, source_attr=None, reverse_dependency=False): """ @@ -192,11 +204,13 @@ class Collector(object): field = related.field if field.rel.on_delete == DO_NOTHING: continue - sub_objs = self.related_objects(related, new_objs) - if self.can_fast_delete(sub_objs, from_field=field): - self.fast_deletes.append(sub_objs) - elif sub_objs: - field.rel.on_delete(self, field, sub_objs, self.using) + batches = self.get_del_batches(new_objs, field) + for batch in batches: + sub_objs = self.related_objects(related, batch) + if self.can_fast_delete(sub_objs, from_field=field): + self.fast_deletes.append(sub_objs) + elif sub_objs: + field.rel.on_delete(self, field, sub_objs, self.using) for field in model._meta.virtual_fields: if hasattr(field, 'bulk_related_objects'): # Its something like generic foreign key. -- cgit v1.3