public function addField($field, $alias = null)
{
if ($field instanceof ISelectExpression) {
$this->addExpression($field);
} else {
if (is_scalar($field)) {
$this->addExpression(FieldSelectExpression::create($field, $alias));
} else {
if (is_array($field)) {
foreach ($field as $fName => $values) {
$expr = new ConcatSelectExpression();
$expr->setPropertyArray($values);
$expr->setAlias($fName);
$this->addExpression($expr);
}
} else {
throw new \InvalidArgumentException("Invalid field type entered");
}
}
}
return $this;
}
