在 MySQL 中更新记录时，Laravel 的 useCurrent() 不起作用

Question

I have recently added a new migration to my database which in its simplest form does something like this

If(Schema::hasTable('some_table')){
    Schema::table('some_table', function (Blueprint $table) {
        $table->dateTime('last_updated')->nullable(false)->useCurrent()->change();
    });
}

According to this answer on SE, Laravel should automatically create and updated the last_record column for me but I am testing this in MySQL 5.7.31 and this is definitely not the case for me. I am using Laravel 7.5 and my PHP version is 7.3.21.

Meanwhile, adding CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP manually to my database failed as well. So, it seems that it might be an issue with my MySQL database instead of Laravel itself. So, I have two questions:

Is it possible to somehow use Laravel/PHP to always add a default value to a field when nothing is passed on insert or update?

Edit: @lagbox asked about how I am saving/updating records in my database. Here is how

$record= TableModel::where('blah', $blah)
                ->first();

if($record){
    $record->update([
         'blah1' => $blah1,
         'blah2' => $blah2
    ]);
}

Answer 1

You can override the fields that are used for the created_at and updated_at timestamps on the Model that Eloquent will automatically handle:

const UPDATED_AT = 'last_updated';

You can also disable a particular timestamp by setting the const to null :

const CREATED_AT = null;

Laravel 7.x Docs - Eloquent - Model Conventions - Timestamps UPDATED_AT CREATED_AT