@John_Betong It has nothing to do with PHP, it’s Mysql’s strict mode.
@felgall Looks like Mysql at last started setting Srict Mode in the default configuration, just like Maria DB is doing already.
If you want to revert it to the default behavior, you may set sql_mode in mysql server’s my.cnf to an empty string (or list there the settings you find appropriate).
Thanks. I think I’ll leave it the way it is - there shouldn’t be many instances where I slipped up and didn’t set the correct type in the first place so there shouldn’t be too many errors and it will mean that I’ll get all the code fixed properly before the live server gets upgraded to the same.