atk4\data\Field_SQL::getDSQLExpression PHP Method

    public function getDSQLExpression($expression)
    {
        if (isset($this->owner->persistence_data['use_table_prefixes'])) {
            return $expression->expr('{}.{}', [$this->join ? isset($this->join->foreign_alias) ? $this->join->foreign_alias : $this->join->short_name : (isset($this->owner->table_alias) ? $this->owner->table_alias : $this->owner->table), $this->actual ?: $this->short_name]);
        } else {
            // references set flag use_table_prefixes, so no need to check them here
            return $expression->expr('{}', [$this->actual ?: $this->short_name]);
        }
    }