Add GROUP_CONCAT aggregate function to views

Can we have a list of entity links instead of list of strings? It would be very useful too.

This is actually a long standing issue and other than turning in into a MR so that we can easily update it with the latest module commits, I don't think this will ever get into core. The main reason is that GROUP_CONCAT() is only valid for MySQL databases. PostreSQL has STRING_AGG() and SQL Server requires some strange stuff to accomplish it.

So, from what I understand, we have only a few options here.

Either implement a solution taking into account the database type, either invoke a hook/event/plugin/something to allow other custom or contrib modules to add their own solutions. Contrib modules are more easy to target a specific database than core.

The patch was not working anymore on drupal 11, rewrote the patch and also fix a couple other comments since the patch was fixing that too.

Drupal in #43 was also working for Drupal 10.3.1,
but Drupal 10.3.2 brings some clean up of comments in views module. Patch in #43 includes some of these that are therefore not needed anymore => removed from this patch

Hello~ firstly I would like to acknowledge the hard work of everyone in this thread, working towards adding string aggregation support to Drupal Views. The feature is often needed and the work is much appreciated.

However, as noted by vensires in comment #42 I agree it is unlikely that this feature will be added to Drupal Views core, because it depends upon database engine specific implementation details which are better suited to contrib.

I have therefore taken the liberty and gone ahead to wrap, crediting the good work done in this thread into a new standalone contrib module providing Views string aggregation support.

A release candidate has been added and is available for viewing here:

https://www.drupal.org/project/views_string_aggregation →