function toDialectString(IDialect $dialect)
{
if (empty($this->set)) {
return null;
}
$values = new SqlValueExpressionArray($this->set);
$compiledSlices = array();
$compiledSlices[] = '(';
$compiledSlices[] = $this->subject->toDialectString($dialect);
$compiledSlices[] = ')';
$compiledSlices[] = $this->operator->toDialectString($dialect);
$compiledSlices[] = '(';
$compiledSlices[] = $values->toDialectString($dialect);
$compiledSlices[] = ')';
$compiledString = join(' ', $compiledSlices);
return $compiledString;
}
