README

PHP面向对象数据库包装器。设计用于（成为）兼容多个数据库。查询是用PHP编写的，表与模型相连。

先决条件/要求

• PHP >=7.4（目前如此）
• 一个MySQL数据库（含表）
• PDO

安装

J0113/ODB可以使用composer进行安装。

composer require j0113/odb *

入门指南

1. 数据库连接

你首先想做的事情是设置与数据库的连接。这将设置整个应用程序的数据库连接。

use J0113\ODB\PDODatabase;
PDODatabase::connect("server.localhost", "myusername", "mypassword", "mydatabase");

2. 映射一个模型

所有模型都必须扩展J0113\ODB\PDODatabaseObject。

use J0113\ODB\PDODatabaseObject;
class User extends PDODatabaseObject
{
    // First you may define a table (defaults to the className)
    protected const TABLE = "users";

    // Than some fields:
    protected ?string $username = null;
    protected ?string $firstname = null;
    protected ?string $lastname = null;
    
    // Maybe some relations (more about that later)
    protected const RELATIONS = [
        "orders" => ["toOne", "Order", "user_id", "id"],
    ];
    
    // And getters and setters
    public function getUsername() : ?string
        ... 
}

这就对了，现在你可以以面向对象的方式从PHP访问数据库了。

用法

1. 插入

$user = new User();
$user->setFirstname("John");
$user->setLastname("Smith");
$user->setUsername("john_smith");

$user->save();

echo $user->getId();

2. 获取数据

要获取数据，必须使用J0113\ODB\QueryBuilder，如果支持更多数据库，查询也将得到支持。

use J0113\ODB\QueryBuilder;

/**
 * Get some users and display info
 * @param QueryBuilder
 * @return User[]|null
 */
$users = User::get(
    (new QueryBuilder())
        ->where("firstname", "John")
        ->andWhere("lastname", "Smith")
        ->limit(5)
);

if (!empty($users)){
    foreach ($users as $user){
        echo "Hello " . $user->getFirstname() . "!\n";
    }
}

/**
 * Get one user
 * @param QueryBuilder
 * @return User|null
 */
$user = User::getOne(
    (new QueryBuilder())->where("username", "oliver12345")
);

3. 更新一行

要更新数据，过程大致相同，只需保持ID不变并使用save()。

use J0113\ODB\QueryBuilder;

/**
 * Get one user
 * @param QueryBuilder
 * @return User|null
 */
$user = User::getOne(
    (new QueryBuilder())->where("username", "oliver12345")
);
$user->setFirstname("Oli");
$user->save();

关系

将数据库映射到PHP对象的一个问题是，当关系发挥作用时。ODB采用即时编译（JIT）方法，相关对象在PHP中是“可访问”的，但只有在被访问时才会执行查询。

关系在模型对象中使用protected const RELATIONS数组定义，关系可以是toOne或toMany。

use J0113\ODB\PDODatabaseObject;
use J0113\ODB\QueryBuilder;
class User extends PDODatabaseObject
{
    /**
     * Stores all the relations, these are read only and results in more than one query IF the relation is queried.
     * Must be an sub array with "key" => ["type", "class", "column", "property"].
     * - Key: is under what $obj->key the relation can be accessed.
     * - Type: can be toOne (this-1) or toMany (this-multiple)
     * - Class: the class it should be connected to (must be an child of PDODatabaseObject)
     * - Column: the column it should search in
     * - Property: the value to match against, is a property (or variable) of the current object
     *
     * SQL will generated by:
     * - LIMIT: Type
     * - FROM: Class
     * - WHERE: column = this->property
     *
     * protected const RELATIONS = ["customer" => ["toOne", "Model\User", "id", "user_id"] ];
     * $order->customer = Model\User(...)
     *
     * Tip: Use the PHPDoc '@ property' to let the IDE know about the relation.
     *
     * @var array
     */
    protected const RELATIONS = [
        "orders" => ["toMany", "Order", "user_id", "id"]
        // $this->orders would result in Order::get((new QueryBuilder())->where("user_id", $this->id));
    ];
    
    /**
     * You may use a getter
     * @return Order[]
     */
    public function getOrders() : array
    {
        return $this->orders;
    }
}

$user = User::getOne((new QueryBuilder()));
$user_orders = $user->getOrders();

许可

J0113/ODB根据Apache 2.0许可发布。有关详情，请参阅附带的LICENSE文件。