/**
* SelectExpression ::=
* IdentificationVariable | StateFieldPathExpression |
* (AggregateExpression | "(" Subselect ")" | FunctionDeclaration) [["AS"] AliasResultVariable]
*
* @return \Doctrine\ORM\Query\AST\SelectExpression
*/
public function SelectExpression()
{
$expression = null;
$fieldAliasIdentificationVariable = null;
$peek = $this->_lexer->glimpse();
// First we recognize for an IdentificationVariable (DQL class alias)
if ($peek['value'] != '.' && $peek['value'] != '(' && $this->_lexer->lookahead['type'] === Lexer::T_IDENTIFIER) {
$expression = $this->IdentificationVariable();
} else {
if (($isFunction = $this->_isFunction()) !== false || $this->_isSubselect()) {
if ($isFunction) {
if ($this->_isAggregateFunction($this->_lexer->lookahead['type'])) {
$expression = $this->AggregateExpression();
} else {
$expression = $this->FunctionDeclaration();
}
} else {
$this->match(Lexer::T_OPEN_PARENTHESIS);
$expression = $this->Subselect();
$this->match(Lexer::T_CLOSE_PARENTHESIS);
}
if ($this->_lexer->isNextToken(Lexer::T_AS)) {
$this->match(Lexer::T_AS);
}
if ($this->_lexer->isNextToken(Lexer::T_IDENTIFIER)) {
$token = $this->_lexer->lookahead;
$fieldAliasIdentificationVariable = $this->AliasResultVariable();
// Include AliasResultVariable in query components.
$this->_queryComponents[$fieldAliasIdentificationVariable] = array('resultVariable' => $expression, 'nestingLevel' => $this->_nestingLevel, 'token' => $token);
}
} else {
// Deny hydration of partial objects if doctrine.forcePartialLoad query hint not defined
if ($this->_query->getHydrationMode() == Query::HYDRATE_OBJECT && !$this->_query->getHint(Query::HINT_FORCE_PARTIAL_LOAD)) {
throw DoctrineException::partialObjectsAreDangerous();
}
$expression = $this->StateFieldPathExpression();
}
}
return new AST\SelectExpression($expression, $fieldAliasIdentificationVariable);
}
