'datetime' casted attribute returning current date from am empty string in the db

[NabilHassen]

Laravel Version

11.5.0

PHP Version

8.3.4

Database Driver & Version

SQLite 3.19.1 for Windows 11

Description

When an empty string is persisted on a datetime column in the database and that column is casted by 'datetime' cast, you get current datetime instead of null as the output.

Steps To Reproduce

1. create a migration which includes a datetime column as such:
   $table->dateTime('approved_at')->nullable();
2. On the model class, cast the attribute using 'datetime' cast as such:
   protected function casts(): array { return [ 'approved_at' => 'datetime', ]; }
3. Let us assume that we have a Post model and store some date as such:
   Post::create(['title' => 'Laravel', 'approved_at' => '']);
4. And finally, let's try to access the 'approved_at' field as such:
   $post->approved_at;

Expected result: null or ''
Outcome: current datetime (i.e. same as now() method)

[Tofandel]

Shouldn't it be Post::create(['title' => 'Laravel', 'approved_at' => null]); if your field is nullable

[NabilHassen]

Shouldn't it be Post::create(['title' => 'Laravel', 'approved_at' => null]); if your field is nullable

@Tofandel

Using Livewire for example, if you set a date on the standard html datepicker and then clear it, then an empty string is passed instead of null.

I don't know what happens with just regular blade code, didn't try it.

[Tofandel]

If you use the validator with nullable rule and retrieve the validated fields that should convert empty strings to null

[marius-mcp]

This is news for me.... so nullable strings can't be empty strings from laravel's perspective....
This is one argument against using validated array then in this case.
And this is a monolithic approach... Is this the same in lumen?

[NabilHassen]

Already did that, no difference.

[crynobone]

This seems to be a Livewire issue instead of a bug for Laravel Framework. Feel free to continue the discussion for now.

[NabilHassen]

@crynobone @Tofandel

$post = Post::create(['title' => 'Laravel', 'approved_at' => '']); and approved_at is datetime casted.
Shouldn't $post->approved_at be null or empty string ? It is returning current datetime instead!!!

I'm curious:
Isn't this a bug? If not, what is it?
And what does this have to do with Livewire?

[Tofandel]

Did you make sure that you don't have attributes in the mysql column like ON CREATE CURRENT_DATETIME?

[NabilHassen]

As soon as I remove the datetime cast, it works.

[marius-mcp]

Try Carbon::parse('')->toDateTimeString(). See if it returns now.
I remember strange behavior of this parse in the past, when if I would parse the 'a' character I would get now.
This is one of the reasons that made me NEVER use casts and when comparing, I cast anything (except null) that comes from db to string and compare string with string (or null).

[Tofandel]

You can use setApprovedAtAttribute and do some logic there to convert empty string to null and the rest Carbon::parse it as a workaround but yes it does sound like a bug, though one with 0% chance of being fixed because touching the date casts is completely frowned upon now with the potential breaking change