Strict mode (aka STRICT_TRANS_TABLES
) makes the database, well, more strict when it comes to manipulating data.
In my case, an older PHP app was inserting new rows, but because some column values were not specified on the PHP side AND those columns did not have a "default" value set in the database, it threw an error.
Fixing this "the right way" wasn't really possible, so I wanted to just disable the strict mode.