Optimizing MySQL query with group_concat
I have an old PHP5 MySQL webapp whose code had to be adapted to PHP8/MySQL14.14 There's a view, querying few tables and based on that code: (SELECT `db_demandes`.`bdd`.`id` AS `Id`, `db_demandes`.`bdd`.`ref` AS `Ref`, `db_demandes`.`bdd`.`nodossier` AS `NoDossier`, `db_demandes`.`bdd`.`agentfirme` AS `Agentfirme`, `db_demandes`.`bdd`.`agentanterieur`…