Multiple Databases example suggest explaining migrate requires --database be specified for non-default

[Tom Weber]

In the Multiple Databases section of the documentation it would be extremely helpful to know that the migrate command must be run for each database with --database= for any non-default database. It took me some time to discover this through a stack-overflow post.

This affects all versions.

​https://docs.djangoproject.com/en/2.2/topics/db/multi-db/#an-example

​https://stackoverflow.com/questions/35609509/django-migrations-with-multiple-databases

Thanks, I hope this helps the community.

[James Malcolm]

I believe the behaviour is documented here, under the ​Synchronizing your databases section. Where it says:

The migrate management command operates on one database at a time. By default, it operates on the default database, but by providing the --database option, you can tell it to synchronize a different database.

Perhaps though, we could add a line in the "An Example" section referencing the need to specify the database? Especially since that StackOverflow article has been viewed 13k times.

[Tom Weber]

Replying to JamesTrick:

I believe the behaviour is documented here, under the ​Synchronizing your databases section. Where it says:

The migrate management command operates on one database at a time. By default, it operates on the default database, but by providing the --database option, you can tell it to synchronize a different database.

Perhaps though, we could add a line in the "An Example" section referencing the need to specify the database? Especially since that StackOverflow article has been viewed 13k times.

Django is such a big project, that even though the documentation contains all the information I have ever needed, it is not always where I need it considering related subjects. A reference to the associated migrate section and reminder to specifically run the migrate command for each database would have helped in my scenario.

[Carlton Gibson]

Especially since that StackOverflow article has been viewed 13k times.

I think that's probably the essence of it. I edited the SO Answer to link back to the correct docs section, and opened a ​PR to link back there from the Example section lower down.

Hopefully that should help people find the docs in question.

[GitHub <noreply@…>]

In 1b32b2f:

Fixed #32083 -- Added link back to migrating section in multi-db docs example.

[Carlton Gibson <carlton.gibson@…>]

In d1f791d:

[3.1.x] Fixed #32083 -- Added link back to migrating section in multi-db docs example.

Backport of 1b32b2f614c5c45f4a0f270ae7273c2d8e16617b from master