Quote Originally Posted by lat9 View Post
With those 'mixed' collations, you need to start based on what DB_CHARSET is currently indicated in the site's configure.php files. Given that the majority of the tables are utf8mb4_general_ci, the DB_CHARSET should indicate utf8mb4.

Since it's only a few 'outlying' tables, here's my suggestion:

1. Put the site into maintenance mode.
2. Make (and verify) a database backup via phpMyAdmin.
3. Using your webhost's phpMyAdmin, select the current live database and
a. Click the Operations tab at the top.
b. Towards the bottom of the screen, you should see a "Collation" sub-tab. Choose utf8mb4_general_ci, tick the "Change all tables collations" and, once that's clicked, also click the "Change all tables columns collations" and click the "Go" button.
4. Visually verify the validity of the fields present in those (what were) latin1_/utf8_ tables/fields. If they look OK, make yet another DB backup and then take the site out of maintenance mode.
Oh! Brilliant advise! I was trying to figure out how to do this in an efficient way. Thanks so much! Have a great weekend! :)