Question

我有一个存储库函数，我想使用CASE WHEN THEN THEN，但是doctrine不允许在ELSE中使用NULL。当然，我用谷歌搜索，但我找不到答案如何避免它。

public function countAverageOdd($user) {
    return $this->getEntityManager()
                    ->createQuery('
                            SELECT
                                avg(
                                    CASE
                                        WHEN p.homeAway = \'h\' AND p.moneyline IS NOT NULL THEN m.home
                                        WHEN p.homeAway = \'d\' AND p.moneyline IS NOT NULL THEN m.draw
                                        WHEN p.homeAway = \'e\' AND p.moneyline IS NOT NULL THEN m.away
                                        WHEN p.homeAway = \'h\' AND p.spread IS NOT NULL THEN s.home
                                        WHEN p.homeAway = \'e\' AND p.spread IS NOT NULL THEN s.away
                                        WHEN p.homeAway = \'h\' AND p.total IS NOT NULL THEN t.over
                                        WHEN p.homeAway = \'e\' AND p.total IS NOT NULL THEN t.under
                                    ELSE NULL
                                    END
                                    )
                            FROM
                                AppBundle:Predictions p
                                LEFT JOIN p.moneyline m
                                LEFT JOIN p.spread s
                                LEFT JOIN p.total t
                            WHERE p.user = :user ')
                    ->setParameter(":user", $user)
                    ->setMaxResults(1)
                    ->getSingleScalarResult();
}

错误： [语法错误]第0行，第900列：错误：意外“空”

https://github.com/doctrine/doctrine2/issues/3160

doctrinebot于2013年5月22日发表评论

问题以“无法修复”

的分辨率结束

请给我建议。

Answer 1

我设法通过传入null值作为参数来绕过Doctrines逻辑检查。这是一个黑客，但它似乎是唯一有效的，。

public function countAverageOdd($user) {
    return $this->getEntityManager()
                    ->createQuery('
                            SELECT
                                avg(
                                    CASE
                                        WHEN p.homeAway = \'h\' AND p.moneyline IS NOT NULL THEN m.home
                                        WHEN p.homeAway = \'d\' AND p.moneyline IS NOT NULL THEN m.draw
                                        WHEN p.homeAway = \'e\' AND p.moneyline IS NOT NULL THEN m.away
                                        WHEN p.homeAway = \'h\' AND p.spread IS NOT NULL THEN s.home
                                        WHEN p.homeAway = \'e\' AND p.spread IS NOT NULL THEN s.away
                                        WHEN p.homeAway = \'h\' AND p.total IS NOT NULL THEN t.over
                                        WHEN p.homeAway = \'e\' AND p.total IS NOT NULL THEN t.under
                                    ELSE :null
                                    END
                                    )
                            FROM
                                AppBundle:Predictions p
                                LEFT JOIN p.moneyline m
                                LEFT JOIN p.spread s
                                LEFT JOIN p.total t
                            WHERE p.user = :user ')
                    ->setParameters(array(":user"=> $user,":null"=>NULL))
                    ->setMaxResults(1)
                    ->getSingleScalarResult();

Answer 2

结帐myql case operator documentation。 ELSE是可选的，因此您可以将其删除

public function countAverageOdd($user) {
    return $this->getEntityManager()
                    ->createQuery('
                            SELECT
                                avg(
                                    CASE
                                        WHEN p.homeAway = \'h\' AND p.moneyline IS NOT NULL THEN m.home
                                        WHEN p.homeAway = \'d\' AND p.moneyline IS NOT NULL THEN m.draw
                                        WHEN p.homeAway = \'e\' AND p.moneyline IS NOT NULL THEN m.away
                                        WHEN p.homeAway = \'h\' AND p.spread IS NOT NULL THEN s.home
                                        WHEN p.homeAway = \'e\' AND p.spread IS NOT NULL THEN s.away
                                        WHEN p.homeAway = \'h\' AND p.total IS NOT NULL THEN t.over
                                        WHEN p.homeAway = \'e\' AND p.total IS NOT NULL THEN t.under

                                    END
                                    )
                            FROM
                                AppBundle:Predictions p
                                LEFT JOIN p.moneyline m
                                LEFT JOIN p.spread s
                                LEFT JOIN p.total t
                            WHERE p.user = :user ')
                    ->setParameter(":user", $user)
                    ->setMaxResults(1)
                    ->getSingleScalarResult();

Answer 3

另一种方法是使用NULLIF，即supported。例如

CASE WHEN WHEN p.homeAway = \'h\' THEN 'xyz' ELSE NULLIF(1,1) END

从https://github.com/doctrine/orm/issues/5801#issuecomment-336132280那里得到了

谢谢！

教义案例，那么这是空的

3 个答案: