phprs\ezsql\impls\OnDuplicateKeyUpdateImpl::setExpr PHP Method

    public function setExpr($context, $expr, $args)
    {
        $prefix = '';
        if ($this->first) {
            $this->first = false;
            $prefix = 'ON DUPLICATE KEY UPDATE ';
        } else {
            $prefix = ',';
        }
        $context->appendSql("{$prefix}{$expr}", $prefix == 'ON DUPLICATE KEY UPDATE ');
        $context->appendParams($args);
    }