Subclass query building about single-table-inheritance

[joshbruce]

I made the following, which seems to work:

class Base extends Model
{
    public static function allQuery($columns = ['*'])
    {
        if (!in_array(static::class, static::$singleTableSubclasses)) {
            $query = null;
            foreach(static::$singleTableSubclasses as $subClass) {
                if (is_null($query)) {
                    $query = static::where('type', $subClass::$singleTableType);

                } else {
                    $query->orWhere('type', $subClass::$singleTableType);

                }
            }
            return $query;
        }
        return static::where('type', static::$singleTableType);
    }

    public static function all($columns = ['*']) 
    {
        return static::allQuery($columns)->get();
    }
}

This allows you to do something like:

Base::all()

/*
\Collection {
    all: [
        \Sub { }
        \SubAlt { }
    ]
}
*/

Sub::all()
/*
\Collection {
    all: [
        \Sub { }
    ]
}
*/

SubAlt::all()
/*
\Collection {
    all: [
        \SubAlt { }
    ]
}
*/

Believe this could be added to the trait itself and accomplish the same goal, but I'm not sure it's the most elegant solution.

[joshbruce]

Second iteration:

• Uses DB.
• Allows columns specification.
• Cleaner implementation overall.
• Takes better advantage of developer settable properties.

    public static function query($columns = ['*'])
    {
        $obj = new static();
        $query = DB::table($obj->table)->select($columns);
        if (in_array(static::class, static::$singleTableSubclasses)) {
            $query = $query->where(static::$singleTableTypeField, static::$singleTableType);
        }
        return $query;
    }

    public static function all($columns = ['*']) 
    {
        return static::query($columns)->get();
    }

Going to be adding this to my own trait internal to my project. I have a mental note to submit a PR, but cannot promise timing and want to make sure I'm covering as many use cases as possible using my own project as the guinea pig first.

[jonspalmer]

I can't reproduce the error you describe and have added test that proves it works today dd0668b.