id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
28117	Add a helpful message to loaddata when psycopg2 raises ValueError due to NUL characters in data	Nicolas Kuttler	Srinivas Reddy Thatiparthy	"I have a site that currently uses mysql. The `admin.logentry` table contains `object_repr` values from spam submissions like 

`\u589f0\u0005\u0001\u0000\u0000: Nice article`

While migrating the site to postgres importing fixtures created with dumpdata raises a `ValueError` originating in (I think) https://github.com/psycopg/psycopg2/blob/2_7_1/psycopg/utils.c#L58 and not handled in https://github.com/django/django/blob/stable/1.11.x/django/core/management/commands/loaddata.py#L181

One possible fix, to give users a more informative error message, would be to catch ValueErrors as well on that line.

{{{
Traceback (most recent call last):
  File ""./src/manage.py"", line 8, in <module>
    execute_from_command_line(sys.argv)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/core/management/__init__.py"", line 367, in execute_from_command_line
    utility.execute()
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/core/management/__init__.py"", line 359, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/core/management/base.py"", line 294, in run_from_argv
    self.execute(*args, **cmd_options)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/core/management/base.py"", line 345, in execute
    output = self.handle(*args, **options)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/core/management/commands/loaddata.py"", line 64, in handle
    self.loaddata(fixture_labels)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/core/management/commands/loaddata.py"", line 104, in loaddata
    self.load_label(fixture_label)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/core/management/commands/loaddata.py"", line 167, in load_label
    obj.save(using=self.using)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/core/serializers/base.py"", line 201, in save
    models.Model.save_base(self.object, using=using, raw=True, **kwargs)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/db/models/base.py"", line 824, in save_base
    updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/db/models/base.py"", line 889, in _save_table
    forced_update)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/db/models/base.py"", line 939, in _do_update
    return filtered._update(values) > 0
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/db/models/query.py"", line 654, in _update
    return query.get_compiler(self.db).execute_sql(CURSOR)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py"", line 1148, in execute_sql
    cursor = super(SQLUpdateCompiler, self).execute_sql(result_type)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py"", line 835, in execute_sql
    cursor.execute(sql, params)
  File ""/srv/www/project/staging/20170422-113847/virtualenv/local/lib/python2.7/site-packages/django/db/backends/utils.py"", line 64, in execute
    return self.cursor.execute(sql, params)
ValueError: Problem installing fixture '/srv/www/project/data.json': A string literal cannot contain NUL (0x00) characters.
}}}"	Cleanup/optimization	closed	Core (Management commands)	1.11	Normal	fixed			Ready for checkin	1	0	0	0	0	0