CPerfQueryWhere::parse

function parse($sql)
{
	//Transform and simplify sql
	//
	//Remove balanced braces around equals
	$sql = $this->_remove_braces(CPerfQuery::removeSpaces($sql));

	//Replace "expr1 =  or expr1 =  or expr1 =  ..."
	//with "expr1 in (, ...)"
	$new_sql = preg_replace_callback("/\( (".$this->equation_regex."(?: OR ".$this->equation_regex.")+) \)/i", array($this, "_or2in"), CPerfQuery::removeSpaces($sql));
	if ($new_sql !== null)
		$sql = CPerfQuery::removeSpaces($new_sql);

	//Replace IN with no more than 5 values to equal
	$sql = preg_replace("/ IN[ ]*\([ ]*([0-9]+|'[^']*')([ ]*,[ ]*([0-9]+|'[^']*')[ ]*){0,5}[ ]*\)/i", " = \1 ", $sql);

	//Remove complex inner syntax
	while (preg_match("/\([^()]*\)/", $sql))
		$sql = preg_replace("/\([^()]*\)/", "", $sql);

	$this->simplified_sql = $sql;

	foreach (preg_split("/ and /i", $sql) as $str)
	{
		$match = array();
		if (preg_match("/(".$this->table_aliases_regex."\.[`"\[\]]{0,1}[a-zA-Z0-9_]+[`"\[\]]{0,1}) = (".$this->table_aliases_regex."\.[`"\[\]]{0,1}[a-zA-Z0-9_]+[`"\[\]]{0,1})/", $str, $match))
		{
			$join = new CPerfQueryJoin;
			$join->parse_left($match[1]);
			$join->parse_right($match[2]);
			$this->joins[] = $join;
		}
		elseif (preg_match("/(".$this->table_aliases_regex."\.[`"\[\]]{0,1}[a-zA-Z0-9_]+[`"\[\]]{0,1}) = ([0-9]+|'.+')/", $str, $match))
		{
			$join = new CPerfQueryJoin;
			$join->parse_left($match[1]);
			$join->parse_right($match[2]);
			$this->joins[] = $join;
		}
	}

	return !empty($this->joins);
}