diff --git a/django/core/management.py b/django/core/management.py
index 0c69c61f8e..a22384782c 100644
--- a/django/core/management.py
+++ b/django/core/management.py
@@ -200,42 +200,31 @@ def _get_many_to_many_sql_for_model(klass):
def get_sql_delete(app):
"Returns a list of the DROP TABLE SQL statements for the given app."
- from django.db import backend, connection, models, transaction
-
+ from django.db import backend, connection, models, get_introspection_module
+ introspection = get_introspection_module()
+
+ # This should work even if a connecton isn't available
try:
cursor = connection.cursor()
except:
cursor = None
-
- # Determine whether the admin log table exists. It only exists if the
- # person has installed the admin app.
- try:
- if cursor is not None:
- # Check whether the table exists.
- cursor.execute("SELECT 1 FROM %s LIMIT 1" % backend.quote_name('django_admin_log'))
- except:
- # The table doesn't exist, so it doesn't need to be dropped.
- transaction.rollback_unless_managed()
- admin_log_exists = False
+
+ # Figure out which tables already exist
+ if cursor:
+ table_names = introspection.get_table_list(cursor)
else:
- admin_log_exists = True
+ table_names = []
output = []
-
+
# Output DROP TABLE statements for standard application tables.
to_delete = set()
references_to_delete = {}
app_models = models.get_models(app)
for klass in app_models:
- try:
- if cursor is not None:
- # Check whether the table exists.
- cursor.execute("SELECT 1 FROM %s LIMIT 1" % backend.quote_name(klass._meta.db_table))
- except:
- # The table doesn't exist, so it doesn't need to be dropped.
- transaction.rollback_unless_managed()
- else:
+ if cursor and klass._meta.db_table in table_names:
+ # The table exists, so it needs to be dropped
opts = klass._meta
for f in opts.fields:
if f.rel and f.rel.to not in to_delete:
@@ -244,61 +233,57 @@ def get_sql_delete(app):
to_delete.add(klass)
for klass in app_models:
- try:
- if cursor is not None:
- # Check whether the table exists.
- cursor.execute("SELECT 1 FROM %s LIMIT 1" % backend.quote_name(klass._meta.db_table))
- except:
- # The table doesn't exist, so it doesn't need to be dropped.
- transaction.rollback_unless_managed()
- else:
- output.append("DROP TABLE %s;" % backend.quote_name(klass._meta.db_table))
- if backend.supports_constraints and references_to_delete.has_key(klass):
- for rel_class, f in references_to_delete[klass]:
- table = rel_class._meta.db_table
- col = f.column
- r_table = klass._meta.db_table
- r_col = klass._meta.get_field(f.rel.field_name).column
- output.append('ALTER TABLE %s DROP CONSTRAINT %s;' % \
- (backend.quote_name(table),
- backend.quote_name("%s_referencing_%s_%s" % (col, r_table, r_col))))
- del references_to_delete[klass]
+ if cursor and klass._meta.db_table in table_names:
+ # Drop the able now
+ output.append("DROP TABLE %s;" % backend.quote_name(klass._meta.db_table))
+ if backend.supports_constraints and references_to_delete.has_key(klass):
+ for rel_class, f in references_to_delete[klass]:
+ table = rel_class._meta.db_table
+ col = f.column
+ r_table = klass._meta.db_table
+ r_col = klass._meta.get_field(f.rel.field_name).column
+ output.append('ALTER TABLE %s DROP CONSTRAINT %s;' % \
+ (backend.quote_name(table),
+ backend.quote_name("%s_referencing_%s_%s" % (col, r_table, r_col))))
+ del references_to_delete[klass]
# Output DROP TABLE statements for many-to-many tables.
for klass in app_models:
opts = klass._meta
for f in opts.many_to_many:
- try:
- if cursor is not None:
- cursor.execute("SELECT 1 FROM %s LIMIT 1" % backend.quote_name(f.m2m_db_table()))
- except:
- transaction.rollback_unless_managed()
- else:
+ if cursor and f.m2m_db_table() in table_names:
output.append("DROP TABLE %s;" % backend.quote_name(f.m2m_db_table()))
app_label = app_models[0]._meta.app_label
# Delete from django_package, auth_permission, django_content_type.
- # TODO: fix this when permissions are activated again
- # output.append("DELETE FROM %s WHERE %s = '%s';" % \
- # (backend.quote_name('auth_permission'), backend.quote_name('package'), app_label))
- output.append("DELETE FROM %s WHERE %s = '%s';" % \
- (backend.quote_name('django_content_type'), backend.quote_name('app_label'), app_label))
+ if cursor and "django_content_type" in table_names:
- # Delete from the admin log.
- if cursor is not None:
- cursor.execute("SELECT %s FROM %s WHERE %s = %%s" % \
- (backend.quote_name('id'), backend.quote_name('django_content_type'),
- backend.quote_name('package')), [app_label])
- if admin_log_exists:
- for row in cursor.fetchall():
+ # Grab a list of affected content-types
+ cursor.execute("SELECT id FROM django_content_type WHERE app_label = %s", [app_label])
+ affected_content_types = [r[0] for r in cursor.fetchall()]
+
+ # Remember do this this business in reverse order since the returned
+ # values are reversed below
+ output.append("DELETE FROM %s WHERE %s = '%s';" % \
+ (backend.quote_name('django_content_type'), backend.quote_name('app_label'), app_label))
+
+ if "auth_permission" in table_names:
+ for ctype_id in affected_content_types:
output.append("DELETE FROM %s WHERE %s = %s;" % \
- (backend.quote_name('django_admin_log'), backend.quote_name('content_type_id'), row[0]))
+ (backend.quote_name("auth_permission"), backend.quote_name("content_type_id"), ctype_id))
+ # Delete from the admin log.
+ if "django_admin_log" in table_names:
+ for ctype_id in affected_content_types:
+ output.append("DELETE FROM %s WHERE %s = %s;" % \
+ (backend.quote_name("django_admin_log"), backend.quote_name("content_type_id"), ctype_id))
+
# Close database connection explicitly, in case this output is being piped
# directly into a database client, to avoid locking issues.
- cursor.close()
- connection.close()
+ if cursor:
+ cursor.close()
+ connection.close()
return output[::-1] # Reverse it, to deal with table dependencies.
get_sql_delete.help_doc = "Prints the DROP TABLE SQL statements for the given app name(s)."
@@ -492,13 +477,7 @@ def reset(app):
app_name = app.__name__.split('.')[-2]
# First, try validating the models.
- s = StringIO()
- num_errors = get_validation_errors(s, app)
- if num_errors:
- sys.stderr.write("Error: %s couldn't be installed, because there were errors in your model:\n" % app_name)
- s.seek(0)
- sys.stderr.write(s.read())
- sys.exit(1)
+ _check_for_validation_errors(app)
sql_list = get_sql_reset(app)
confirm = raw_input("""