/**
* Checks whether the $model exists in the database.
*
* @param string $targetClass the name of the ActiveRecord class that should be used to validate the uniqueness
* of the current attribute value.
* @param array $conditions conditions, compatible with [[\yii\db\Query::where()|Query::where()]] key-value format.
* @param Model $model the data model to be validated
*
* @return bool whether the model already exists
*/
private function modelExists($targetClass, $conditions, $model)
{
/** @var ActiveRecordInterface $targetClass $query */
$query = $this->prepareQuery($targetClass, $conditions);
if (!$model instanceof ActiveRecordInterface || $model->getIsNewRecord() || $model->className() !== $targetClass::className()) {
// if current $model isn't in the database yet then it's OK just to call exists()
// also there's no need to run check based on primary keys, when $targetClass is not the same as $model's class
$exists = $query->exists();
} else {
// if current $model is in the database already we can't use exists()
/** @var $models ActiveRecordInterface[] */
$models = $query->select($targetClass::primaryKey())->limit(2)->all();
$n = count($models);
if ($n === 1) {
$keys = array_keys($conditions);
$pks = $targetClass::primaryKey();
sort($keys);
sort($pks);
if ($keys === $pks) {
// primary key is modified and not unique
$exists = $model->getOldPrimaryKey() != $model->getPrimaryKey();
} else {
// non-primary key, need to exclude the current record based on PK
$exists = reset($models)->getPrimaryKey() != $model->getOldPrimaryKey();
}
} else {
$exists = $n > 1;
}
}
return $exists;
}