/**
*
* @throws PDOException
*/
public function _query()
{
if ($this->_rowset === false) {
if (self::$_stmt) {
while (self::$_stmt->nextRowset()) {
//如果已经在结果缓存中，则搜寻结果集
$query = array_shift(self::$_fetchingQueue);
$query->_rowset = $query->_fetchAll();
if ($query === $this) {
return;
}
}
self::$_stmt = null;
}
//将当前的语句插到第一个，然后把所有语句一口气打包发送给mysql
$keys = array_keys(self::$_waitingQueue, $this);
if (count($keys)) {
unset(self::$_waitingQueue[$keys[0]]);
}
$sql = $this->_select->assemble();
if (count(self::$_waitingQueue)) {
$sql .= ";\n" . implode(";\n", self::$_waitingQueue);
}
implode(";\n", self::$_waitingQueue);
self::$_stmt = $this->_select->getAdapter()->query($sql);
$this->_rowset = $this->_fetchAll();
self::$_fetchingQueue = self::$_waitingQueue;
self::$_waitingQueue = array();
}
}
/**
* Performs a validation on the select query before passing back to the parent class.
* Ensures that only columns from the primary DataObject are returned in the result.
*
* @return string|null This object as a SELECT string (or null if a string cannot be produced)
*/
public function assemble()
{
if (count($this->_parts[self::UNION]) == 0) {
$fields = $this->getPart(Select::COLUMNS);
$primary = $this->_info[DataObject::NAME];
$schema = $this->_info[DataObject::SCHEMA];
// If no fields are specified we assume all fields from primary table
if (!count($fields)) {
$this->from($primary, self::SQL_WILDCARD, $schema);
}
}
return parent::assemble();
}
