当运行下面的DQL时,我需要帮助只选择Doctrine 2中的鉴别器列。
SELECT p.type FROM AppBundle\Entity\Product p
type
是实体AppBundle\Entity\Product
中的鉴别器列。
@ORM\DiscriminatorColumn(name="type", type="smallint")`
@ORM\DiscriminatorMap({
"0" = "AppBundle\Entity\Product",
"1" = "AppBundle\Entity\Product\SingleIssue",
"2" = "AppBundle\Entity\Product\CountBasedIssue",
"3" = "AppBundle\Entity\Product\TimeBasedIssue"
})
我知道实体中type
不是真正的属性,但有没有办法让我这样做?
提前感谢!
更新
经过两天阅读Doctrine代码后,我决定通过以下片段覆盖SqlWalker并创建新的Hydrator。
覆盖SqlWalker
<?php
namespace ...;
use Doctrine\ORM\Query\SqlWalker;
class CustomSqlWalker extends SqlWalker
{
const FORCE_GET_DISCRIMINATOR_COLUMN = 'forceGetDiscriminatorColumn';
const DISCRIMINATOR_CLASS_MAP = 'discriminatorClassMap';
/**
* {@inheritdoc}
*/
public function walkSelectClause($selectClause)
{
$sql = parent::walkSelectClause($selectClause);
$forceGetDiscriminatorColumn = $this->getQuery()->getHint(self::FORCE_GET_DISCRIMINATOR_COLUMN);
if (empty($forceGetDiscriminatorColumn)) {
return $sql;
}
foreach ($this->getQueryComponents() as $key => $queryComponent) {
if (!in_array($key, $forceGetDiscriminatorColumn)) {
continue;
}
$metadata = $queryComponent['metadata'];
$discriminatorColumn = $metadata->discriminatorColumn['name'];
$tableName = $metadata->table['name'];
$tableAlias = $this->getSQLTableAlias($tableName, $key);
$discriminatorColumnAlias = $this->getSQLColumnAlias($discriminatorColumn);
$sql .= ", $tableAlias.$discriminatorColumn AS $discriminatorColumnAlias";
}
return $sql;
}
}
自定义水合器
<?php
namespace ...;
use Doctrine\ORM\Internal\Hydration\ArrayHydrator;
use PDO;
class CustomHydrator extends ArrayHydrator
{
/**
* {@inheritdoc}
*/
protected function hydrateAllData()
{
$result = array();
$rootClassName = null;
if (isset($this->_hints['forceGetDiscriminatorColumn']) &&
isset($this->_hints['discriminatorClassMap'])) {
$rootClassName = $this->_hints['discriminatorClassMap'];
}
while ($data = $this->_stmt->fetch(PDO::FETCH_ASSOC)) {
foreach ($data as $key => $value) {
if ($this->hydrateColumnInfo($key) != null ||
empty($rootClassName)) {
continue;
}
$metadata = $this->getClassMetadata($rootClassName);
$discriminatorColumn = $metadata->discriminatorColumn;
$fieldName = $discriminatorColumn['fieldName'];
$type = $discriminatorColumn['type'];
$this->_rsm->addScalarResult(
$key, $fieldName, $type
);
}
$this->hydrateRowData($data, $result);
}
return $result;
}
}
Configure custom hydrator
orm:
...
hydrators:
CustomHydrator: YourNamespace\To\CustomHydrator
最后一步
$query = $queryBuilder->getQuery();
$query->setHint(\Doctrine\ORM\Query::HINT_CUSTOM_OUTPUT_WALKER, 'YourNamespace\To\CustomSqlWalker');
$query->setHint(\YourNamespace\To\CustomSqlWalker::FORCE_GET_DISCRIMINATOR_COLUMN, array($rootAlias)); // this alias will be used in CustomSqlWalker class
$query->setHint(\YourNamespace\To\CustomSqlWalker::DISCRIMINATOR_CLASS_MAP, $this->getClassName()); // this full-qualify class name will be used in CustomHydrator class
$products = $query->getResult('CustomHydrator');
简而言之
我知道这个解决方案可能很复杂(也许只适用于我的情况),所以我希望有人能给我另一种简单的方法来解决这个问题,非常感谢!
INSTANCE OF
似乎是最干净的解决方案,但我的第一个想法是将鉴别器列加倍,其中一个Doctrine不会掩盖。 好吧,那很丑陋,并且需要确保两个列不能脱节,但它具有让您根据需要处理数据的优点。 - Balmipour