Document that some DATABASES['OPTIONS'] are not passed to dbshell database shell.

[Simon Charette]

Some of DATABASES['OPTIONS'] (e.g. ​isolation_level) are not passed to the the underlying shell.

In the long run I think we should try to add support for as many as of them as possible but since this will likely require and some time and discussion we should at least document the limitation.

For context, we spent a good amount of trying to figure out why SELECT @@TX_ISOLATION was returning a REPEATABLE-READ while we had set isolation_level = 'read committed' in our OPTIONS.

I think it might be more discoverable if the a note was added beside DATABASES['OPTIONS'] instead of dbshell` as that's where we initially looked but that's just anecdotal evidence.

[Farhaan Bukhsh]

Hey, I would like to work on this issue. I might need some clarification since I am a new contributor. Let me know if I am doing this right, adding documentation saying some options might not be available around DATABASES['OPTIONS'] instead near dbshell will make it better, right?

Thanks for the help in advance. :joy:

[Simon Charette]

Hello Farhaan, thanks for giving a shot at this ticket!

I'm not sure where of the best place is for the documentation to live but I have a slight preference for dbshell since I can't think of another place where we special case connection creation and that was I looked for when trying to figure out what was happening.

I guess a ..note pointing to DATABASE_OPTIONS mentioning some options will be ignored because should do.

[Farhaan Bukhsh]

Hey Simon, thanks for replying :) I was thinking something similar may be a list of all options which is not passed near the dbshell documentation. What do you think?

[Simon Charette]

I was thinking something similar may be a list of all options which is not passed near the dbshell documentation. What do you think?

I think it will be hard to come up with this list for all backends and maintain it over time as some of them are directly passed to the underlying connector.

[Farhaan Bukhsh]

Replying to Simon Charette:

I was thinking something similar may be a list of all options which is not passed near the dbshell documentation. What do you think?

I think it will be hard to come up with this list for all backends and maintain it over time as some of them are directly passed to the underlying connector.

So I can just link dbshell with DATABASE_OPTIONS pointing out that some options might be ignored, I will open a PR for this.

[Farhaan Bukhsh]

Hey Simon according to the documentation ​https://docs.djangoproject.com/en/2.2/ref/databases/#isolation-level%20isolation_level the default is READ COMMITTED so the behaviour you should have got by default in dbshell should be READ COMMITTED, do you think this is another bug or am I missing something?

[Simon Charette]

The MySQL server we were connecting to doesn't default to READ COMMITTED hence why we used DATABASES['OPTIONS']['isolation_level'] = 'read committed' to make sure connections managed by Django have their isolation level set to the right value.

This option is ignored by dbshell which is the reason for this ticket's existence.

[Mariusz Felisiak <felisiak.mariusz@…>]

In cc5622ec:

Fixed #30865 -- Doc'd that not all DATABASESOPTIONS are passed to command-line client.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 64b01e38:

[3.0.x] Fixed #30865 -- Doc'd that not all DATABASESOPTIONS are passed to command-line client.

Backport of cc5622ec8c260535c63279cf6eb293f2b5a742f0 from master

[Mariusz Felisiak <felisiak.mariusz@…>]

In 398a9f42:

[2.2.x] Fixed #30865 -- Doc'd that not all DATABASESOPTIONS are passed to command-line client.

Backport of cc5622ec8c260535c63279cf6eb293f2b5a742f0 from master