grum wrote:

I am wondering if it's possible with a plugin to alter a table.

Currently, there are plugins doing this:

* [extension by P@t] Additional Pages (add a value in the history.section enum field)
* [extension by P@t] Lightbox (add a column in the history table)
* [extension by P@t] Has High (add a value in the history.section enum field)
* [extension by mistic100] Colored Tags (add a column in the tags table)
* [extension by rub] Web services statistics (add a value in the history.section enum field)
* [extension by P@t] Most Commented (add a value in the history.section enum field)
* [extension by rvelices] RV Maps & Earth (add columns in the images table)

(I find them after a "svn checkout http://piwigo.org/extensions; find extensions -name maintain.inc.php | xargs grep -i alter")

For my first plugin [extension by plg] Community, I've created a dedicated table, but I could have added a column in the users_infos table. I just got inspiration from [extension by Eric] UserAdvManager.

I think that adding a column has no consequence on upgrades. We don't check the list of columnsin order to stop the process if we get too many columns (but we list the existing columns to "discover" which version is running).

I was not aware that so many plugins were modifying the history.section column. And this is a problem. It will clearly break if the next upgrade updates the column. We should think of another way to list the possible sections than an enum field. I'll open a topic for this specific problem and invite plugin authors.

For the plugin [extension by ddtddt] Meta I add a column to the table *_categories.

This plant is adding image to users who wrote in this table.

It is better, it seems to me, not to add a column in existing table