|
public scalar ( |
||
| $db | the MongoDB connection used to generate the query. If this parameter is not given, the `mongodb` application component will be used. | |
| return | string | null | false | the value of the first column in the first row of the query result. `false` is returned if the query result is empty. |
public function scalar($db = null)
{
$originSelect = (array) $this->select;
if (!isset($originSelect['_id']) && array_search('_id', $originSelect, true) === false) {
$this->select['_id'] = false;
}
$cursor = $this->buildCursor($db);
$row = $this->fetchRows($cursor, false);
if (empty($row)) {
return false;
}
return reset($row);
}