语义错误 - 学说2.0

Question

这些都是我的表：

Table Gift: 
     -id 
     -price 
     ... 

Table Couple: 
     -id 
     -name 
     ... 

table registry: //provide a many-many relation between gifts and couples 
     -id 
     -coupleId 
     -giftId 

table purchase: 
     -amount 
     -registryId 

我已经写了一个SQL查询来获取所有的礼物信息特定夫妇

$qb = $this->createQueryBuilder('g') //gift 
    ->from('\BBB\GiftBundle\Entity\Registry', 'reg') 
    ->select('g.id , g.price') 
    ->where('reg.gift = g.id') 
    ->andWhere('reg.couple = :coupleID') 
    ->orderBy('reg.id','DESC') 
    ->setParameter('coupleID', $coupleID); 

OR

 SELECT g.id , g.price, 
    FROM gift g, registry reg  
    WHERE reg.gift_id = g.id AND reg.couple_id = 1 

我也想至获得已购买礼品的总金额（如有）
EX。 SUM（purchase.amount）作为totalContribute

我曾尝试：

$qb = $this->createQueryBuilder('g') 
    ->from('\BBB\GiftBundle\Entity\Purchase', 'p') 
    ->from('\BBB\GiftBundle\Entity\Registry', 'reg') 
    ->select('g.id , g.price') 
    ->addSelect('SUM(p.amount) as totalContribute') 
    ->leftJoin('p','pp', 'ON','reg.id = pp.registry') 
    ->where('reg.gift = g.id') 
    ->andWhere('reg.couple = :coupleID') 
    ->orderBy('reg.id','DESC') 
    ->setParameter('coupleID', $coupleID); 

，但它给了我下面的错误：

[Semantical Error] line 0, col 145 near 'pp ON reg.id': Error: Identification Variable p used in join path expression but was not defined before. 

Answer 1

首先，你应该定义在连接条件的连接后的SQL语句，不在WHERE子句中。原因是它真的没有效率。因此，查询建议立即进行删除样子：

SELECT g.id , g.price, 
FROM gift g JOIN registry reg ON reg.gift_id = g.id 
WHERE reg.couple_id = 1 

但你的学说查询时，你得到错误，因为你定义在错误的方式连接。您的查询应该更像：

$qb = $this->createQueryBuilder('g') // You don't have put "from" beacuse I assume you put this into GiftRepository and then Doctrine knows that should be \BBB\GiftBundle\Entity\Gift 
    ->select('g.id , g.price') 
    ->addSelect('SUM(p.amount) as totalContribute') 
    ->join('g.purchase','p')   // pay attention for this line: you specify relation basing on entity property - I assume that is "$purchase" for this example   
    ->leftJoin('p.registry', 'reg') // here you join with \BBB\GiftBundle\Entity\Purchase 
    ->where('reg.couple = :coupleID') 
    ->orderBy('reg.id','DESC') 
    ->setParameter('coupleID', $coupleID); 

请将此视为伪 - 我没有检查它的工作原理，但它应该更喜欢这样。

还有一件事 - 如果您的存储库方法返回X实体的对象，则应该将此方法放入XRepository。