Laravel 5如何在select子句中使用Carbon转换与日期相关的列？

I am new to php and laravel and using laravel 5.2 with MariaDB 10.1.xx.

test table has index and date (yyyymmdd) columns.

I would like to convert date format from yyyymmdd to YYYYmm without using raw query in the select clause.

I tried it as following:

$test = DB::table('test')
->select( 'idx',Carbon::parse('date')->format('Ym') );

and got error as below:

DateTime::__construct(): Failed to parse time string (date) at position 0 (n): The timezone could not be found in the database.

Please let me have any idea to solve this issue using carbon not raw query.

In your model (Test) add the protected field $dates:

class Test {
    //...
    protected $dates = ['created_at', 'updated_at', 'date'];
    //...
}

This tells Eloquent that the field date (and the default timestamp-fields) contains a date. $entity->date will now contain a Carbon instance for an entity of type Test. You can use this to format the date ($entity->date->format('Ym');)

You could even write an Accessor to do this for you:

class Test {
    //...
    public function getFormattedDateAttribute() {
        return $this->attributes['date']->format('Ym');
    }
    //...
}

echo $entity->formatted_date;

Other option is to use mutators in your model something like

public function getDateAttribute($value){
    return Carbon::createFromFormat('Y-m-d', $value)->toDateTimeString();

}

You can change or work with it as you need