How to query the latest associated model of a model with specific conditions in Laravel?

I just asked a question on StackOverflow, please answer it.

http://stackoverflow.com/ques...

A Package model has many Step models. There are two fields in Step, the tinyint type status field and the timestamp field.
Suppose a Package A has the following steps

• At 10 o'clock on the 18th, status is 1

• At 9:00 on the 19th, status is 2

Suppose a Package B has the following steps

• At 8:00 on the 19th, status is 1

• At 9:00 on the 19th, status is 2

• At 10 o'clock on the 19th, status is 3

In this way, the latest step status of A is 2, and the latest step status of B is 3.

Then, how to query the packages whose latest step status is 2?

I tried adding

to the package model

<code>public function steps()
{
    return $this->hasMany('App\Step');
}

public function status()
{
    return $this->steps()->latest()->limit(1);
}
</code>

Then query like this

<code>Package::whereHas('status', function ($q) {
    $q->where('status', 2);
})->get();
</code>

But I can’t get the expected results.

The so-called not expected result means that if there is only B in the packages table, I want to query the packages whose latest step status is 2, and the latest step status of B is 3, so the result should be empty, but the result of querying like this is not It is not empty, but contains B.

Then I tried to change to

<code>public function status()
{
    return $this->hasOne('App\Step')->latest();
}
</code>

It’s still the same.

I just learned Laravel, and I was very confused when I encountered this problem. I also searched a lot of Google, but I couldn’t find the answer I wanted. I hope you can help me, thank you!

Using Laravel 5.3

Reply content:

I just asked a question on StackOverflow, please answer it.

http://stackoverflow.com/ques...

A Package model has many Step models. There are two fields in Step, the tinyint type status field and the timestamp field.
Suppose a Package A has the following steps

• At 10 o'clock on the 18th, status is 1

• At 9:00 on the 19th, status is 2

Suppose a Package B has the following steps

• At 8:00 on the 19th, status is 1

• At 9:00 on the 19th, status is 2

• At 10 o'clock on the 19th, status is 3

In this way, the latest step status of A is 2, and the latest step status of B is 3.

Then, how to query the packages whose latest step status is 2?

I tried adding

to the package model

<code>public function steps()
{
    return $this->hasMany('App\Step');
}

public function status()
{
    return $this->steps()->latest()->limit(1);
}
</code>

Then query like this

<code>Package::whereHas('status', function ($q) {
    $q->where('status', 2);
})->get();
</code>

But I can’t get the expected results.

The so-called not expected result means that if there is only B in the packages table, I want to query the packages whose latest step status is 2, and the latest step status of B is 3, so the result should be empty, but the result of querying like this is not It is not empty, but contains B.

Then I tried to change to

<code>public function status()
{
    return $this->hasOne('App\Step')->latest();
}
</code>

It’s still the same.

I just learned Laravel, and I was very confused when I encountered this problem. I also searched a lot of Google, but I couldn’t find the answer I wanted. I hope you can help me, thank you!

Using Laravel 5.3

<code>Package::whereHas('steps', function ($q) {
    $q->where('status', 2);
})->get();</code>