Question

我正在为我创建2个模型的端点/项目的输出构建REST API：

项目：

class Projects extends BaseModel
{
    public function initialize()
    {
        $this->hasMany('id', 'Participants', 'projectId');
    }
}

参加者：

class Participants extends BaseModel
{
    public function initialize()
    {
        $this->belongsTo('projectId', 'Projects', 'id');
    }
}

让我们说，我有10个项目：（1个查询）

$results = Projects::find();

我遍历了所有10个，但我也想要所有参与者：

foreach($results as $result) {
    echo $result->participants; // 1 query
}

因此，在循环结束时，Phalcon为每个项目进行了额外的查询。

这些查询是通过在迭代10个项目时访问$ result-＆gt;参与者来完成的：

SELECT IF(COUNT(*)>0, 1 , 0) FROM `INFORMATION_SCHEMA`.`TABLES` WHERE `TABLE_NAME`='projects'
DESCRIBE `projects`
SELECT `projects`.`id`, `projects`.`title`, `projects`.`client`, `projects`.`color`, `projects`.`start_date`, `projects`.`end_date`, `projects`.`notes`, `projects`.`stateId`, `projects`.`created_at`, `projects`.`updated_at` FROM `projects`
SELECT IF(COUNT(*)>0, 1 , 0) FROM `INFORMATION_SCHEMA`.`TABLES` WHERE `TABLE_NAME`='project_participants'
DESCRIBE `project_participants`
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0
SELECT `project_participants`.`id`, `project_participants`.`project_id`, `project_participants`.`user_id`, `project_participants`.`user_role_id`, `project_participants`.`user_state_id`, `project_participants`.`updated_at`, `project_participants`.`created_at` FROM `project_participants` WHERE `project_participants`.`project_id` = :0

问题

有没有办法事先查询关系，所以它将是一个查询。当我使用Phalcon提供的查询生成器时，我无法以相同的方式访问 - ＆gt;参与者。

修改

我最终使用了Query Builder，命名所有列

$builder = $modelsManager->createBuilder();
$builder->columns($columns)
        ->from('Projects')
        ->leftJoin('Participants')
        ->getQuery()
        ->execute();

这样的列：

Projects.id as projects_id
...
Participants.id as participants_id
Participants.projectId as participants_projectId

由于在查询生成器创建的结果上访问 - ＆gt;参与者，也进行了额外的查询。

Answer 1

要使用QueryBuilder以相同的方式访问 - ＆gt;参与者，您必须构建连接到Query。

代码示例可能类似于：

$queryBuilder = $this->getDI()->getModelsManager()
    ->createBuilder()
    ->columns(['p.id','participants.*'])
    ->addFrom('Entity\Projects', 'p')
    ->leftJoin('Entity\Participants', 'participants.projectId = p.id', 'participants')
    ->groupBy('p.id, participants.id')
    ->orderBy('p.id ASC');

$resultSet = $queryBuilder->getQuery()->execute();

这里使用

groupBy() by来使结果可能是多维的。

这种查询（在PgSQL下测试）使Phalcon在项目pi的Resultsets中为参与者p创建了一些后续的ResultSet对象。

您仍然可以使用foreach()进行迭代，但毕竟我不确定它是否确实减少了最终查询次数。

Fire $result = $resultSet->toArray()使$result['pi']仍为Resultset，所以你应该对此保持谨慎。 您可以通过在columns()参数中定义确切列来强制它作为数组转储。它有其缺点 - 您将不再从groupBy()获利，至少在Phalcon 1.3上。 2和PHP 5.5.3我在这里运行。

Answer 2

有一个很棒的图书馆可以快速加载phalcon。

stibiumz phalcon eager loading

该库解决了关系的N + 1查询。它已经包含在phalcon孵化器中。我已经在生产中使用它了。

它的作用是使用IN子句创建一个查询，并用结果填充模型。

有很多事情：

SELECT * FROM main
SELECT * FROM related WHERE x.id IN (results from the previous resultset)

Phalcon性能相关查询

问题

修改

2 个答案: