Django使用manage.py备份与恢复数据

Django dumpdata and loaddata

django

database

model

dumpdata

dumpdata command

• It is a django management command, which can be use to backup(export) you model instances or whole database

dumpdata for basic database dump

• Following command will dump whole database in to a db.json file

./manage.py dumpdata > db.json

dumpdata for backup specific app

• Following command will dump the content in django admin app into admin.json file

./manage.py dumpdata admin > admin.json

dumpdata for backup specific table

• Following command will dump only the content in django admin.logentry table

./manage.py dumpdata admin.logentry > logentry.json

• Following command will dump the content in django auth.user table

./manage.py dumpdata auth.user > user.json

dumpdata (--exclude)

• You can use --exclude option to specify apps/tables which don't need being dumped

• Following command will dump the whole database with out including auth.permission table content

./manage.py dumpdata --exclude auth.permission > db.json

dumpdata (--indent)

• By default, dumpdata will output all data on a single line. It isn’t easy for humans to read

• You can use the --indent option to pretty-print the output with a number of indentation spaces

./manage.py dumpdata auth.user --indent 2 > user.json

• Example output of above command is below

dumpdata (--format)

• By default, dumpdata will format its output in JSON

• You can specify the format using --format option

• Command supports for following formats(serialization formats)

1. json
2. xml
3. yaml

./manage.py dumpdata auth.user --indent 2 --format xml > user.xml

• Above command output an xml file(user.xml)

loaddata command

• This command can be use to load the fixtures(database dumps) into database

./manage.py loaddata user.json

• This command will add the user.json file content into the database

Restore fresh database

• When you backup whole database by using dumpdata command, it will backup all the database tables

• If you use this database dump to load the fresh database(in another django project), it can be causes IntegrityError (If you loaddata in same database it works fine)

• To fix this problem, make sure to backup the database by excluding contenttypes and auth.permissions tables

./manage.py dumpdata --exclude auth.permission --exclude contenttypes > db.json

• Now you can use loaddata command with a fresh database

./manage.py loaddata db.json