Equivalent of Records in Craft 3? Trying to convert a plugin from Craft 2 to Craft 3, not sure what's the Records equivalent in Craft 3.
How do I get this to work in C3?
class SearchRelationshipRecord extends BaseRecord
{
    public function tableName()
    {
        return 'some_name';
    }

    protected function setAttributes()
    {
        return [
            'aaa' =&gt; AttributeType::Number,
            'bbb' =&gt; AttributeType::Number,
            'ccc' =&gt; AttributeType::String
        ];
    }

    public function defineIndexes()
    {
        return [
            ['columns' =&gt; ['aaa']],
            ['columns' =&gt; ['bbb']],
            ['columns' =&gt; ['aaa', 'ccc']],
            ['columns' =&gt; ['bbb', 'ccc']],
        ];
    }
}
/**
 * Class SearchRelationship record
 *
 * @property int $id
 * @property int $aaa
 * @property int $bbb
 * @property string $ccc
*/
class SearchRelationship extends ActiveRecord
{
    /**
     * @inheritdoc
     * @return string
     */
    public static function tableName(): string
    {
        return '{{%somename}}';
    }
}

All you really need to define is the table name.  Yii 2 uses reflection on the database table to generate the column/object property names at runtime (replacing the old setAttributes method).
Worth reading: https://www.yiiframework.com/doc/guide/2.0/en/db-active-record
Indexes should be initially defined in your plugin's install migration (replacing defineIndexes).