This patch will:
* Store the current schema definition as a serialized array in the database, indexed by table
* Compare the current schema S(t) to schema S(t + 1)
* Allow transformational updates to happen to the data to ease the transition

Update procedure:
* Add entirely new schema components.
* Allow hook_update_N() to run any changes to update the data.
* Remove obsolete schema components.
* Make schema modifications that don't involve additions or removals.

Comments

moshe weitzman’s picture

moshe weitzman commented

does this patch exist yet? would be swell :)

schema.module attempts to do some of this. it is in Contrib for now.

wim leers’s picture

wim leers
Location Ghent 🇧🇪🇪🇺
commented

Subscribing.

Frando’s picture

Frando commented

Very interesting. Subscribing. If there's already some code, I'll gladly review it.

morphir’s picture

morphir commented

adding to my tracker.

bjaspan’s picture

bjaspan commented

Subscribing; didn't know abut this patch until now.

I've been thinking along these lines from the very beginning, but it seemed like too much to put into D6. Note that as Moshe says, a lot of the code for this is already written though it is not necessarily organized usefully yet:

- Comparing schema N to N+1 (or any two schema structures) is in schema.module.
- Updating a single field to match the schema is in database.{mysql-common,pgsql}.inc in db_change_field() and db_update_field(). Iterating over that for all fields would be simple.

Currently, all data type transformations for existing fields are handled by the db directly via UPDATE SET new_col = old_col which means any non-trivial update will just lose all data (and probably throw SQL errors). We may want to define our own behavior for that so that, as influenced by the dabbledb.com 7-minute demo, we can handle (say) string->datetime conversion or whatever.

bjaspan’s picture

bjaspan commented
Version: 6.x-dev » 7.x-dev
Crell’s picture

Crell commented
Version: 7.x-dev » 8.x-dev
alansaviolobo’s picture

alansaviolobo commented
Issue summary: View changes
Issue tags: +Schema API

Version: 8.0.x-dev » 8.1.x-dev

Drupal 8.0.6 was released on April 6 and is the final bugfix release for the Drupal 8.0.x series. Drupal 8.0.x will not receive any further development aside from security fixes. Drupal 8.1.0-rc1 is now available and sites should prepare to update to 8.1.0.

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Drupal 8.1.9 was released on September 7 and is the final bugfix release for the Drupal 8.1.x series. Drupal 8.1.x will not receive any further development aside from security fixes. Drupal 8.2.0-rc1 is now available and sites should prepare to upgrade to 8.2.0.

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Bug reports should be targeted against the 8.3.x-dev branch from now on, and new development or disruptive changes should be targeted against the 8.4.x-dev branch. For more information see the Drupal 8 minor version schedule and the Allowed changes during the Drupal 8 release cycle.

Version: 8.3.x-dev » 8.4.x-dev

Drupal 8.3.6 was released on August 2, 2017 and is the final full bugfix release for the Drupal 8.3.x series. Drupal 8.3.x will not receive any further development aside from critical and security fixes. Sites should prepare to update to 8.4.0 on October 4, 2017. (Drupal 8.4.0-alpha1 is available for testing.)

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Version: 8.5.x-dev » 8.6.x-dev

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Version: 8.9.x-dev » 9.2.x-dev

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Version: 9.2.x-dev » 9.3.x-dev

Version: 9.3.x-dev » 9.4.x-dev

Drupal 9.3.15 was released on June 1st, 2022 and is the final full bugfix release for the Drupal 9.3.x series. Drupal 9.3.x will not receive any further development aside from security fixes. Drupal 9 bug reports should be targeted for the 9.4.x-dev branch from now on, and new development or disruptive changes should be targeted for the 9.5.x-dev branch. For more information see the Drupal core minor version schedule and the Allowed changes during the Drupal core release cycle.

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Version: 9.5.x-dev » 11.x-dev

Drupal core is moving towards using a “main” branch. As an interim step, a new 11.x branch has been opened, as Drupal.org infrastructure cannot currently fully support a branch named main. New developments and disruptive changes should now be targeted for the 11.x branch. For more information, see the Drupal core minor version schedule and the Allowed changes during the Drupal core release cycle.

smustgrave’s picture

smustgrave commented
Status: Active » Postponed (maintainer needs more info)
Issue tags: +stale-issue-cleanup

Thank you for creating this issue to improve Drupal.

We are working to decide if this task is still relevant to a currently supported version of Drupal. There hasn't been any discussion here for over 8 years which suggests that this has either been implemented or is no longer relevant. Your thoughts on this will allow a decision to be made.

Since we need more information to move forward with this issue, the status is now Postponed (maintainer needs more info). If we don't receive additional information to help with the issue, it may be closed after three months.

Thanks!

smustgrave’s picture

smustgrave commented
Status: Postponed (maintainer needs more info) » Closed (outdated)

Since there's been no follow up in 3 months going to close out, if still a valid task please re-open

Thanks all!