DQL - 选择多个字段，但只获取一个 - 从结果集中隐藏字段

Question

鉴于以下 DQL 查询：

SELECT
    p,
    (p.views * 0.1) + (p.likes * 0.9) as ratingPhoto
FROM
    AppBundle:Photo p
ORDER BY
    ratingPhoto DESC

我的结果集如下所示：

array (size=14)
  0 => 
    array (size=2)
      0 => object(Photo)
      'ratingPhoto' => string '1.42' (length=4)
  1 => 
    array (size=2)
      0 => object(Photo)
      'ratingPhoto' => string '1.31' (length=4)
...

是否有任何 DQL 功能以便我只检索 Photo 对象并从结果集中排除其他选定的字段？这是我期望的结果：

array (size=14)
  0 => object(Photo)
  1 => object(Photo)
...

Answer 1

您要查找的是 ORDER 子句和 HIDDEN 关键字中的计算值。

通常，您必须执行以下操作：

SELECT
    a,
    b,
    (SOME_COMPUTATION()) AS computed
FROM
    ...
ORDER BY
    computed ASC

要从结果集中“隐藏”computed 值，从 Doctrine ORM 2.3 开始，您可以使用 HIDDEN 子句：

SELECT
    a,
    b,
    (SOME_COMPUTATION()) AS HIDDEN computed
FROM
    ...
ORDER BY
    computed ASC

这就是您的 DQL 的样子：

SELECT 
    p,
    (p.views * 0.1) + (p.likes * 0.9) AS HIDDEN ratingPhoto
FROM
    AppBundle:Photo p
ORDER BY
    ratingPhoto DESC

Answer 2

您可以将 DQL 重写为：

$dql = "SELECT p
FROM AppBundle:Photo p
ORDER BY ((p.views * 0.1) + (p.likes * 0.9)) DESC";