Data export and import

[greenrobot]

Allow an data (and optionally the data model) to be exported and imported. This would simplify packaging an initial dataset with an app.

Possible implementations: json.gz, binary.gz, raw dump.

Update: you can prepare a data.mdb file to have preloaded data in your app; see FAQ.

[yocn]

Wow~ Could you please share some time schedule for this feature？ @greenrobot

[motornyimaksym]

Extremely useful feature! Looking forward!

[bigntallmike]

This would greatly simplify some work I'm doing -- I'd love to just download a fully built MDB file to the app, or some intermediary format that can be "automatically" parsed to replace the on-device database.

[motornyimaksym]

It's weird but this "feature" already available. When I looked for how to do it I found this issue on github and thought that it's impossible to pack initial dataset into my app. But then I noticed question in FAQ section of official site:

Can I ship my app with a pre-built database?
Yes. ObjectBox stores all data in a single database file. Thus, you just need to prepare this DB file and copy it to the correct location on the first start of your app (before you touch ObjectBox’s API). The DB file is called “data.mdb” and is typically located in a subdirectory called “objectbox” (or any name you passed to BoxStoreBuilder). On Android, the DB file is located inside the app’s files directory inside “objectbox/objectbox/” or, for example “objectbox/yourname” if you assigned the custom name “yourname” using BoxStoreBuilder.

As for me it's enough. Maybe it would be useful for thoose who looking for solution.

[yocn]

@Yazon2006 where are you find the FAQ? would you please share the url?

[motornyimaksym]

@yocn in very unexpected place: http://objectbox.io/faq/

[yocn]

@greenrobot So, Is the Can I ship my app with a pre-built database? in FAQ recommend for developers?

[greenrobot-team]

@yocn Yes? Not sure what you are getting at with recommended. -ut

[greenrobot]

So we just double checked: the data.mdb file works across plaforms (x64, ARM, 32 and 64 bit). Thus, the FAQ is still valid.

[yocn]

@greenrobot So,If I want to develop with a preset data.mdb, my process is:
1、I generate a data.mdb with my preset datas.
2、get a default path in data/data/myPackageName/file/objectbox/data.mdb
3、replace the default data.mdb with my data.mdb.
Is this correct?
And does objectbox have a API to get default data.mdb location?

[greenrobot]

Yes, this is mostly correct. Just a few comments:

• It would be better if you would create the file before opening ObjectBox (data.mdb should be non-existent)
• better way to get to the base path is via context.getFilesDir() (don't do "data/data/myPackageName/file")
• default path from the files dir is "/objectbox/objectbox" (the latter "objectbox" is the adjustable db name)
• There's a non-public method BoxStoreBuilder.getAndroidDbDir(), you can take as reference

I think it makes sense to make a convenient method to provision a default db file, that copies some file if the actual db file does not exist. What do you think?