[英]Is there a tool to check database integrity in Django?
为我们的Django站点供电的MySQL数据库产生了一些完整性问题; 例如,引用不存在的行的外键。 我不会谈论我们是如何陷入这种混乱的,但我现在正在研究如何解决这个问题。
基本上, 我正在寻找一个扫描Django站点中所有模型的脚本,并检查所有外键和其他约束是否正确 。 希望问题的数量足够小,以便手动修复。
我可以自己编写代码,但我希望这里有人有更好的主意。
我发现了django-check-constraints,但它不太符合要求:现在,我不需要一些东西来防止这些问题,但要找到它们以便在采取其他步骤之前手动修复它们。
其他限制:
(稍后,我们将转换为InnoDB以获得正确的事务支持,以及可能在数据库级别上的外键约束,以防止将来出现类似问题。但这不是此问题的主题。)
我自己掀起了一些东西。 下面的管理脚本应保存在myapp/management/commands/checkdb.py
。 确保中间目录具有__init__.py
文件。
用法: ./manage.py checkdb
进行全面检查; 使用--exclude app.Model
或-e app.Model
来排除app app
的模型Model
。
from django.core.management.base import BaseCommand, CommandError
from django.core.management.base import NoArgsCommand
from django.core.exceptions import ObjectDoesNotExist
from django.db import models
from optparse import make_option
from lib.progress import with_progress_meter
def model_name(model):
return '%s.%s' % (model._meta.app_label, model._meta.object_name)
class Command(BaseCommand):
args = '[-e|--exclude app_name.ModelName]'
help = 'Checks constraints in the database and reports violations on stdout'
option_list = NoArgsCommand.option_list + (
make_option('-e', '--exclude', action='append', type='string', dest='exclude'),
)
def handle(self, *args, **options):
# TODO once we're on Django 1.2, write to self.stdout and self.stderr instead of plain print
exclude = options.get('exclude', None) or []
failed_instance_count = 0
failed_model_count = 0
for app in models.get_apps():
for model in models.get_models(app):
if model_name(model) in exclude:
print 'Skipping model %s' % model_name(model)
continue
fail_count = self.check_model(app, model)
if fail_count > 0:
failed_model_count += 1
failed_instance_count += fail_count
print 'Detected %d errors in %d models' % (failed_instance_count, failed_model_count)
def check_model(self, app, model):
meta = model._meta
if meta.proxy:
print 'WARNING: proxy models not currently supported; ignored'
return
# Define all the checks we can do; they return True if they are ok,
# False if not (and print a message to stdout)
def check_foreign_key(model, field):
foreign_model = field.related.parent_model
def check_instance(instance):
try:
# name: name of the attribute containing the model instance (e.g. 'user')
# attname: name of the attribute containing the id (e.g. 'user_id')
getattr(instance, field.name)
return True
except ObjectDoesNotExist:
print '%s with pk %s refers via field %s to nonexistent %s with pk %s' % \
(model_name(model), str(instance.pk), field.name, model_name(foreign_model), getattr(instance, field.attname))
return check_instance
# Make a list of checks to run on each model instance
checks = []
for field in meta.local_fields + meta.local_many_to_many + meta.virtual_fields:
if isinstance(field, models.ForeignKey):
checks.append(check_foreign_key(model, field))
# Run all checks
fail_count = 0
if checks:
for instance in with_progress_meter(model.objects.all(), model.objects.count(), 'Checking model %s ...' % model_name(model)):
for check in checks:
if not check(instance):
fail_count += 1
return fail_count
我正在将其作为社区维基,因为我欢迎对我的代码进行任何改进!
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