Phalcon Query Language (PHQL)¶

译者注：学过JAVA，略懂Hibernate的人应该会知道，hibernate是javaee中一个非常流程的ORM软件，它其中生成的中间语句就叫做HQL。

Phalcon查询语言，也可以叫PhalconQL或PHQL，是一个高层次的，允许你使用一种类SQL语言的方式的一种SQL方言。PHQL是一个用C语言编写的SQL语法分析器。

为了达到尽可能高的性能，Phalcon提供了一个分析器，使用了和 SQLite 相同的技术。该技术提供了一个小型的内存分析器，具有非常低的内存占用，同时也是线程安全的。

解析器首先检查传递过来的PHQL语句，然后把它们转化成一种中间性的语句，最后再将其转换为相应的RDBMS所需要的SQL方言。

在PHQL中，我们已经实现了一系列的功能，以保证你在访问数据库时是安全的：

Bound parameters are part of the PHQL language helping you to secure your code
PHQL only allows one SQL statement to be executed per call preventing injections
PHQL ignores all SQL comments which are often used in SQL injections
PHQL only allows data manipulation statements, avoiding altering or dropping tables/databases by mistake or externally without authorization
PHQL implements a high level abstraction allowing you handling models as tables and class attributes as fields

使用示例¶

为了更好的展示PHQL是如何工作的，我们将使用模型 “Cars” 和 “Brands”：

<?php

class Cars extends Phalcon\Mvc\Model
{
    public $id;

    public $name;

    public $brand_id;

    public $price;

    public $year;

    public $style;

   /**
    * This model is mapped to the table sample_cars
    */
    public function getSource()
    {
        return 'sample_cars';
    }

    /**
     * A car only has a Brand, but a Brand have many Cars
     */
    public function initialize()
    {
        $this->belongsTo('brand_id', 'Brands', 'id');
    }
}

每个Car只有一个Brand,一个Brand有多个Cars:

<?php

class Brands extends Phalcon\Mvc\Model
{

    public $id;

    public $name;

    /**
     * The model Brands is mapped to the "sample_brands" table
     */
    public function getSource()
    {
        return 'sample_brands';
    }

    /**
     * A Brand can have many Cars
     */
    public function initialize()
    {
        $this->hasMany('id', 'Cars', 'brand_id');
    }
}

Creating PHQL Queries¶

PHQL查询可以通过实例化 Phalcon\Mvc\Model\Query 来创建：

<?php

// Instantiate the Query
$query = new Phalcon\Mvc\Model\Query("SELECT * FROM Cars");

// Pass the DI container
$query->setDI($di);

// Execute the query returning a result if any
$robots = $query->execute();

在控制器或视图文件中，它可以使用服务容器中的一个注入服务 models manager 来轻松的实现create/execute

<?php

$query = $this->modelsManager->createQuery("SELECT * FROM Cars");

$robots = $query->execute();

或者像下面这样：

<?php

$robots = $this->modelsManager->executeQuery("SELECT * FROM Cars");

Selecting Records¶

作为大家所熟悉的SQL，PHQL允许你在查询中使用SELECT语句，只是需要使用模型类的名称来替代数据表名：

<?php

$query = $manager->createQuery("SELECT * FROM Cars ORDER BY Cars.name");
$query = $manager->createQuery("SELECT Cars.name FROM Cars ORDER BY Cars.name");

带有命名空间的模型类同样可以：

<?php

$phql = "SELECT * FROM Formula\Cars ORDER BY Formula\Cars.name";
$query = $manager->createQuery($phql);

$phql = "SELECT Formula\Cars.name FROM Formula\Cars ORDER BY Formula\Cars.name";
$query = $manager->createQuery($phql);

$phql = "SELECT c.name FROM Formula\Cars c ORDER BY c.name";
$query = $manager->createQuery($phql);

Phalcon支持大部分的SQL标准，甚至是非标准指令，如，LIMIT:

<?php

$phql   = "SELECT c.name FROM Cars AS c "
   . "WHERE c.brand_id = 21 ORDER BY c.name LIMIT 100";
$query = $manager->createQuery($phql);

Results Types¶

根据我们查询列的类型，返回的结果类型会稍有不同。如果你检索一个整体对象，它将返回 Phalcon\Mvc\Model\Resultset\Simple 的对象实例。这种结果集是一组完整的模型对象：

<?php

$phql = "SELECT c.* FROM Cars AS c ORDER BY c.name";
$cars = $manager->executeQuery($phql);
foreach ($cars as $car)
{
    echo "Name: ", $car->name, "\n";
}

这是完全一样的：

<?php

$cars = Cars::find(array("order" => "name"));
foreach ($cars as $car)
{
    echo "Name: ", $car->name, "\n";
}

完整的对象可以被修改和重新保存到数据库，因为他们代表着关联数据表的一个完整记录。有一些其他类型的查询不返回完整的对象，例如：

<?php

$phql = "SELECT c.id, c.name FROM Cars AS c ORDER BY c.name";
$cars = $manager->executeQuery($phql);
foreach ($cars as $car)
{
    echo "Name: ", $car->name, "\n";
}

我们只查询了数据表中的某些字段，因此，这不能算是一个完整的对象。在这种情况下，也返回 Phalcon\Mvc\Model\Resultset\Simple 的实例对象。然而，这个对象只包含两列属性值。

这些值不代表完整的对象，我们称他们为标量。PHQL允许你查询各种类型的标量，如fields,functions,literals, expressions等

<?php

$phql = "SELECT CONCAT(c.id, ' ', c.name) AS id_name FROM Cars AS c ORDER BY c.name";
$cars = $manager->executeQuery($phql);
foreach ($cars as $car)
{
    echo $car->id_name, "\n";
}

我们既可以只查询完整的对象或标量，也可以同时查询他们：

<?php

$phql   = "SELECT c.price*0.16 AS taxes, c.* FROM Cars AS c ORDER BY c.name";
$result = $manager->executeQuery($phql);

在这种情况下，返回的是 Phalcon\Mvc\Model\Resultset\Complex 的实例对象，这允许同时访问完整对象和标量：

<?php

foreach ($result as $row)
{
    echo "Name: ", $row->cars->name, "\n";
    echo "Price: ", $row->cars->price, "\n";
    echo "Taxes: ", $row->taxes, "\n";
}

标量的属性值映射到”row”上，而完整的对象则是被映射到与它相关的模型对象上。

Joins¶

使用PHQL可以很方便的通过多个模型来获取数据，Phalcon支持大多数类型的Joins。我们在模型中定义的关系，在使用PHQL时会自动的添加到条件上：

<?php

$phql  = "SELECT Cars.name AS car_name, Brands.name AS brand_name FROM Cars JOIN Brands";
$rows = $manager->executeQuery($phql);
foreach ($rows as $row)
{
    echo $row->car_name, "\n";
    echo $row->brand_name, "\n";
}

默认情况下，将使用INNER JOIN的方式，你也可以在查询中使用其他类型的JOIN：

<?php

$phql = "SELECT Cars.*, Brands.* FROM Cars INNER JOIN Brands";
$rows = $manager->executeQuery($phql);

$phql = "SELECT CCars.*, Brands.* FROM Cars LEFT JOIN Brands";
$rows = $manager->executeQuery($phql);

$phql = "SELECT Cars.*, Brands.* FROM Cars LEFT OUTER JOIN Brands";
$rows = $manager->executeQuery($phql);

$phql = "SELECT Cars.*, Brands.* FROM Cars CROSS JOIN Brands";
$rows = $manager->executeQuery($phql);

有可能的话，在JOIN中手工设置SQL条件：

<?php

$phql = "SELECT Cars.*, Brands.* FROM Cars INNER JOIN Brands ON Brands.id = Cars.brands_id";
$rows = $manager->executeQuery($phql);

同时，Joins还可以在使用以下方式：

<?php

$phql = "SELECT Cars.*, Brands.* FROM Cars, Brands WHERE Brands.id = Cars.brands_id";
$rows = $manager->executeQuery($phql);
foreach ($rows as $row)
{
    echo "Car: ", $row->cars->name, "\n";
    echo "Brand: ", $row->brands->name, "\n";
}

如果在查询时使用了别名，获取属性值将使用别名的名称做为row的名称：

<?php

$phql = "SELECT c.*, b.* FROM Cars c, Brands b WHERE b.id = c.brands_id";
$rows = $manager->executeQuery($phql);
foreach ($rows as $row)
{
    echo "Car: ", $row->c->name, "\n";
    echo "Brand: ", $row->b->name, "\n";
}

Aggregations¶

下面的示例将展示如何在PHQL中使用聚合：

<?php

// How much are the prices of all the cars?
$phql = "SELECT SUM(price) AS summatory FROM Cars";
$row  = $manager->executeQuery($phql)->getFirst();
echo $row['summatory'];

// How many cars are by each brand?
$phql = "SELECT Cars.brand_id, COUNT(*) FROM Cars GROUP BY Cars.brand_id";
$rows = $manager->executeQuery($phql);
foreach ($rows as $row)
{
    echo $row->brand_id, ' ', $row["1"], "\n";
}

// How many cars are by each brand?
$phql = "SELECT Brands.name, COUNT(*) FROM Cars JOIN Brands GROUP BY 1";
$rows = $manager->executeQuery($phql);
foreach ($rows as $row)
{
    echo $row->name, ' ', $row["1"], "\n";
}

$phql = "SELECT MAX(price) AS maximum, MIN(price) AS minimum FROM Cars";
$rows = $manager->executeQuery($phql);
foreach ($rows as $row)
{
    echo $row["maximum"], ' ', $row["minimum"], "\n";
}

// Count distinct used brands
$phql = "SELECT COUNT(DISTINCT brand_id) AS brandId FROM Cars";
$rows = $manager->executeQuery($phql);
foreach ($rows as $row)
{
    echo $row->brandId, "\n";
}

条件(Conditions)¶

条件的作用是允许你过滤查询内容，WHERE条件可以这样使用：

<?php

// Simple conditions
$phql = "SELECT * FROM Cars WHERE Cars.name = 'Lamborghini Espada'";
$cars = $manager->executeQuery($phql);

$phql = "SELECT * FROM Cars WHERE Cars.price > 10000";
$cars = $manager->executeQuery($phql);

$phql = "SELECT * FROM Cars WHERE TRIM(Cars.name) = 'Audi R8'";
$cars = $manager->executeQuery($phql);

$phql = "SELECT * FROM Cars WHERE Cars.name LIKE 'Ferrari%'";
$cars = $manager->executeQuery($phql);

$phql = "SELECT * FROM Cars WHERE Cars.name NOT LIKE 'Ferrari%'";
$cars = $manager->executeQuery($phql);

$phql = "SELECT * FROM Cars WHERE Cars.price IS NULL";
$cars = $manager->executeQuery($phql);

$phql = "SELECT * FROM Cars WHERE Cars.id IN (120, 121, 122)";
$cars = $manager->executeQuery($phql);

$phql = "SELECT * FROM Cars WHERE Cars.id NOT IN (430, 431)";
$cars = $manager->executeQuery($phql);

$phql = "SELECT * FROM Cars WHERE Cars.id BETWEEN 1 AND 100";
$cars = $manager->executeQuery($phql);

此外，PHQL的另一特点，prepared参数自动转义用户输入数据，下面将介绍的是与安全相关：

<?php

$phql = "SELECT * FROM Cars WHERE Cars.name = :name:";
$cars = $manager->executeQuery($phql, array("name" => 'Lamborghini Espada'));

$phql = "SELECT * FROM Cars WHERE Cars.name = ?0";
$cars = $manager->executeQuery($phql, array(0 => 'Lamborghini Espada'));

Inserting Data¶

PHQL是使用熟悉的INSERT语句插入数据：

<?php

// Inserting without columns
$phql = "INSERT INTO Cars VALUES (NULL, 'Lamborghini Espada', "
      . "7, 10000.00, 1969, 'Grand Tourer')";
$manager->executeQuery($phql);

// Specifyng columns to insert
$phql = "INSERT INTO Cars (name, brand_id, year, style) "
      . "VALUES ('Lamborghini Espada', 7, 1969, 'Grand Tourer')";
$manager->executeQuery($phql);

// Inserting using placeholders
$phql = "INSERT INTO Cars (name, brand_id, year, style) "
      . "VALUES (:name:, :brand_id:, :year:, :style)";
$manager->executeQuery($sql,
    array(
        'name'     => 'Lamborghini Espada',
        'brand_id' => 7,
        'year'     => 1969,
        'style'    => 'Grand Tourer',
    )
);

Phalcon中不只是用PHQL语句转换为SQL语句的。如果我们是手工创建模型对象，里面的所有事件及定义的业务规则都会被执行。现在，我们添加一个模型Cars的业务规则，让car的价格不低于$ 10,000:

<?php

use Phalcon\Mvc\Model\Message;

class Cars extends Phalcon\Mvc\Model
{

    public function beforeCreate()
    {
        if ($this->price < 10000)
        {
            $this->appendMessage(new Message("A car cannot cost less than $ 10,000"));
            return false;
        }
    }

}

如果我们在模型中使用以下的INSERT语句，INSERT操作将不成功，因为价格不符合定义的规则：

<?php

$phql   = "INSERT INTO Cars VALUES (NULL, 'Nissan Versa', 7, 9999.00, 2012, 'Sedan')";
$result = $manager->executeQuery($phql);
if ($result->success() == false)
{
    foreach ($result->getMessages() as $message)
    {
        echo $message->getMessage();
    }
}

更新数据(Updating Data)¶

更新一行记录和插入一行记录非常相似。正如你所知道的，更新数据记录的指令是UPDATE。当更新一行记录时，对应的模型事件将被执行。

<?php

// Updating a single column
$phql = "UPDATE Cars SET price = 15000.00 WHERE id = 101";
$manager->executeQuery($phql);

// Updating multiples columns
$phql = "UPDATE Cars SET price = 15000.00, type = 'Sedan' WHERE id = 101";
$manager->executeQuery($phql);

// Updating multiples rows
$phql = "UPDATE Cars SET price = 7000.00, type = 'Sedan' WHERE brands_id > 5";
$manager->executeQuery($phql);

// Using placeholders
$phql = "UPDATE Cars SET price = ?0, type = ?1 WHERE brands_id > ?2";
$manager->executeQuery(
    $phql,
    array(
        0 => 7000.00,
        1 => 'Sedan',
        2 => 5
    )
);

删除数据(Deleting Data)¶

当删除数据时，对应的模型事件将被执行：

<?php

// Deleting a single row
$phql = "DELETE FROM Cars WHERE id = 101";
$manager->executeQuery($phql);

// Deleting multiple rows
$phql = "DELETE FROM Cars WHERE id > 100";
$manager->executeQuery($phql);

// Using placeholders
$phql = "DELETE FROM Cars WHERE id BETWEEN :initial: AND :final:";
$manager->executeQuery(
    $phql,
    array(
        'initial' => 1,
        'final' => '100
    )
);

使用Query Builder创建queries(Creating queries using the Query Builder)¶

Query Builder可以创建一个PHQL query，而不需要编写PHQL语句了，同时Query Builder对IDE工具是友好的（可以自动提示）：

<?php

$manager->createBuilder()
    >join('RobotsParts');
    ->limit(20);
    ->order('Robots.name')
    ->getQuery()
    ->execute();

与下面是相同的：

<?php

$phql = "SELECT Robots.*
    FROM Robots JOIN RobotsParts p
    ORDER BY Robots.name LIMIT 20";
$result = $manager->executeQuery($phql);

更多关于query builder的示例：

<?php

$builder->from('Robots')
// 'SELECT Robots.* FROM Robots'

// 'SELECT Robots.*, RobotsParts.* FROM Robots, RobotsParts'
$builder->from(array('Robots', 'RobotsParts'))

// 'SELECT * FROM Robots'
$phql = $builder->columns('*')
                ->from('Robots')

// 'SELECT id, name FROM Robots'
$builder->columns(array('id', 'name'))
        ->from('Robots')

// 'SELECT id, name FROM Robots'
$builder->columns('id, name')
        ->from('Robots')

// 'SELECT Robots.* FROM Robots WHERE Robots.name = "Voltron"'
$builder->from('Robots')
        ->where('Robots.name = "Voltron"')

// 'SELECT Robots.* FROM Robots WHERE Robots.id = 100'
$builder->from('Robots')
        ->where(100)

// 'SELECT Robots.* FROM Robots GROUP BY Robots.name'
$builder->from('Robots')
        ->groupBy('Robots.name')

// 'SELECT Robots.* FROM Robots GROUP BY Robots.name, Robots.id'
$builder->from('Robots')
        ->groupBy(array('Robots.name', 'Robots.id'))

// 'SELECT Robots.name, SUM(Robots.price) FROM Robots GROUP BY Robots.name'
$builder->columns(array('Robots.name', 'SUM(Robots.price)'))
    ->from('Robots')
    ->groupBy('Robots.name')

// 'SELECT Robots.name, SUM(Robots.price) FROM Robots
// GROUP BY Robots.name HAVING SUM(Robots.price) > 1000'
$builder->columns(array('Robots.name', 'SUM(Robots.price)'))
    ->from('Robots')
    ->groupBy('Robots.name')
    ->having('SUM(Robots.price) > 1000')

// 'SELECT Robots.* FROM Robots JOIN RobotsParts');
$builder->from('Robots')
    ->join('RobotsParts')

// 'SELECT Robots.* FROM Robots JOIN RobotsParts AS p');
$builder->from('Robots')
    ->join('RobotsParts', null, 'p')

// 'SELECT Robots.* FROM Robots JOIN RobotsParts ON Robots.id = RobotsParts.robots_id AS p');
$builder->from('Robots')
    ->join('RobotsParts', 'Robots.id = RobotsParts.robots_id', 'p')

// 'SELECT Robots.* FROM Robots
// JOIN RobotsParts ON Robots.id = RobotsParts.robots_id AS p
// JOIN Parts ON Parts.id = RobotsParts.parts_id AS t'
$builder->from('Robots')
    ->join('RobotsParts', 'Robots.id = RobotsParts.robots_id', 'p')
    ->join('Parts', 'Parts.id = RobotsParts.parts_id', 't')

// 'SELECT r.* FROM Robots AS r'
$builder->addFrom('Robots', 'r')

// 'SELECT Robots.*, p.* FROM Robots, Parts AS p'
$builder->from('Robots')
    ->addFrom('Parts', 'p')

// 'SELECT r.*, p.* FROM Robots AS r, Parts AS p'
$builder->from(array('r' => 'Robots'))
        ->addFrom('Parts', 'p')

// 'SELECT r.*, p.* FROM Robots AS r, Parts AS p');
$builder->from(array('r' => 'Robots', 'p' => 'Parts'))

// 'SELECT Robots.* FROM Robots LIMIT 10'
$builder->from('Robots')
    ->limit(10)

// 'SELECT Robots.* FROM Robots LIMIT 10 OFFSET 5'
$builder->from('Robots')
        ->limit(10, 5)

Table Of Contents

Previous topic

Next topic

This Page

Phalcon Query Language (PHQL)¶

使用示例¶

Creating PHQL Queries¶

Selecting Records¶

Results Types¶

Joins¶

Aggregations¶

条件(Conditions)¶

Inserting Data¶

更新数据(Updating Data)¶

删除数据(Deleting Data)¶

使用Query Builder创建queries(Creating queries using the Query Builder)¶

Search

Table Of Contents

Previous topic

Next topic

This Page

Phalcon Query Language (PHQL)¶

使用示例¶

Creating PHQL Queries¶

Selecting Records¶

Results Types¶

Joins¶

Aggregations¶

条件(Conditions)¶

Inserting Data¶

更新数据(Updating Data)¶

删除数据(Deleting Data)¶

使用Query Builder创建queries(Creating queries using the Query Builder)¶