public function columnKeys()
    {
        $columnKeys = [];

        foreach ($this->columns() as $key => $column) {
            if (is_string($key)) {
                $columnKeys[] = $key;
            } elseif (str_contains($column, '.')) {
                list($table, $columnKey) = explode('.', $column);
                $columnKeys[]            = $columnKey;
            } else {
                $columnKeys[] = $column;
            }
        }

        return $columnKeys;
    }
public function columnKeys()
    {
        $columnKeys = [];

        foreach ($this->columns() as $key => $column) {
            if (is_string($key)) {
                $columnKeys[] = $key;
            } elseif (str_contains($column, '.')) {
                list($table, $columnKey) = explode('.', $column);
                $columnKeys[]            = $columnKey;
            } else {
                $columnKeys[] = $column;
            }
        }

        return $columnKeys;
    }
public function columnKeys ( ) { $ columnKeys = [ ] ; foreach ( $ this -> columns ( ) as $ key => $ column ) { if ( is_string ( $ key ) ) { $ columnKeys [ ] = $ key ; } elseif ( str_contains ( $ column , '.' ) ) { list ( $ table , $ columnKey ) = explode ( '.' , $ column ) ; $ columnKeys [ ] = $ columnKey ; } else { $ columnKeys [ ] = $ column ; } } return $ columnKeys ; }
Get the keys of columns to be used in the query result.

@return array
Get the keys of columns to be used in the query result .