MongoDB In PHP7

使用 MongoDB 的用户很多，因为它的文档型存储一些变化的内容很方便

在 PHP5 及以前，官方提供了两个扩展，Mongo 和 MongoDB，其中 Mongo 是对以 MongoClient 等几个核心类为基础的类群进行操作，封装得很方便，所以基本上都会选择 Mongo 扩展。

但是随着 PHP 升级到 PHP7，官方不再支持 Mongo 扩展，只支持 MongoDB，所以怎么把 Mongo 无缝替换成 MongoDB 成为了一个亟待解决的问题

MongoDB 引入了命名空间，但是功能封装非常差，如果非要用原生的扩展，几乎意味着写原生的 Mongo 语句

这种想法很违背 ORM 的初衷：简化 DB 操作带来的语法问题而专注逻辑优化

MongoDB 驱动

使用新驱动的部分代码如下：

MongoDbDriver.php
use MongoDB\Driver\WriteConcern;

class MongoDb
{
    //属性略

    public function __construct($config)
    {
        //解析拼接配置过程略
        $this->mongodb = new \MongoDB\Driver\Manager($mongoServer);
        $this->database = $config['database'];
        $this->collection = $config['collection'];
        $this->bulk = new \MongoDB\Driver\BulkWrite();
        $this->writeConcern = new WriteConcern(WriteConcern::MAJORITY, 100);
    }

    public function insert($data = [])
    {
        $this->bulk->insert($data);
        $result = $this->mongodb->executeBulkWrite(
            "$this->database.$this->collection",
            $this->bulk,
            $this->writeConcern
        );

        return $result->getInsertedCount();
    }

    public function delete($where = [], $limit = 1)
    {
        $this->bulk->delete($where, ['limit' => $limit]);
        $result = $this->mongodb->executeBulkWrite(
            "$this->database.$this->collection",
            $this->bulk,
            $this->writeConcern
        );

        return $result->getDeletedCount();
    }

    public function update($where = [], $update = [], $upsert = false)
    {
        $this->bulk->update($where, ['$set' => $update], ['multi' => true, 'upsert' => $upsert]);
        $result = $this->mongodb->executeBulkWrite(
            "$this->database.$this->collection",
            $this->bulk,
            $this->writeConcern
        );

        return $result->getModifiedCount();
    }

    public function query($where = [], $option = [])
    {
        $query = new \MongoDB\Driver\Query($where, $option);
        $result = $this->mongodb->executeQuery("$this->database.$this->collection", $query);

        return json_encode($result);
    }
}

这样的语法和之前差异太大，改动不方便

在这种情况之下，MongoDB 官方为了方便使用，增加市场占有率，推出了基于 MongoDB 扩展的库：mongo-php-library

该库的详细文档见：docs.mongodb.com

composer 下载：

composer require mongodb/mongodb

MongoDB 操作包与旧 Mongo 对比

连接

//old
new MongoClient();
//new
new MongoDB\Client();

新增

//old
$collention->insert($array, $options);
//new
$resultOne = $collention->insertOne($array, $options);//单
$lastId = $resultOne->getInsertedId();
$resultMany = $collention->insertMany($array, $options);//多
$count = $resultMany->getInsertedCount();

修改

//old
$collention->update($condition, [
    '$set' => $values
,[
    'multiple' => true//多条，单条false
]);
//new
$collection->updateOne(
    ['state' => 'ny'],
    ['$set' => ['country' => 'us']]
);
$updateResult = $collection->updateMany(
    ['state' => 'ny'],
    ['$set' => ['country' => 'us']]
);
$count = $updateResult->getModifiedCount();

查询

//old
$cursor = $collection->find($condition, [
    'name' => true//指定字段
]);
$cursor->skip(5);
$cursor->limit(5);
$cursor->sort([
    'time' => -1
]);
//new
$cursor = $collection->find($condition, [
    'skip' => 5,
    'limit' => 5,
    'sort' => [
        'time' => -1
    ],//排序
    'projection' => [
        'name' => 1//指定字段
    ]
]);

删除

//old
$collention->remove($condition, [
    'justOne' => false//删单条
]);
$collention->remove([]);//删所有
//new
$result = $collention->deleteOne($condition, $options);
$collention->deleteMany($condition, $options);

$result->getDeletedCount();

有业务可能需要以类似 MySQL 的自增 ID 来处理数据，PHP5 可能使用的 findAndModify() 方法来查询并修改：

$collention->findAndModify([
    '_id' => $tableName//我在自增表中用其它的表名作主键
], [
    '$inc' => ['id' => 1]//自增
], [
    '_id' => 0
], [
    'new' => 1//返回修改后的结果，默认是修改前的
]);

现在使用 MongoDB 库的话需要修改为：

$collention->findOneAndUpdate([
    '_id' => $tableName
], [
    '$inc' => ['id' => 1]
], [
    'projection' => ['id' => 1],
    'returnDocument' => MongoDB\Operation\FindOneAndUpdate::RETURN_DOCUMENT_AFTER
]);

类似的还有 findOneAndDelete() findOneAndReplace()，更多内容可见 findOneAndUpdate文档

ODM

在开发一个业务中，由于条件非常复杂，会出现各种 $and $or 嵌套，想添加新条件时容易出问题

所以在基类中引入了 ODM，支持链式查询的写法，使查询条件直观易理解

改造了项目中老的 Mongo 操作类，引入了新 Trait

MongoODMTrait.php
trait MongoODM
{
    public $mongoOdm;

    public function connectOdm($db)
    {
        //解析拼接配置过程略
        $client = new \Sokil\Mongo\Client($mongoServer);
        $database = $client->getDatabase($config['database']);
        $this->mongoOdm = new MongoOdm($database);
    }
}

在原有操作类中新增一行 ODM 连接

Mongo.php
use MongoODM;

$this->connectOdm(self::Key);

查询时部分示例代码如下：

QueryTest.php
$collection = $bean->mongoOdm->collection;
$builder = $bean->mongoOdm->find();

$builder->whereIn('sale_id', [1,2,3]);
$builder->where('identity', ['$bitsAnySet' => [$bit]]);

$builder->whereAnd(
    $collection->expression()->whereOr(
        $collection->expression()->whereGreaterOrEqual('last_time', strtotime(date('Y-m-d'))),
        $collection->expression()->whereLike('desc', "{$desc}", true)
    )
);

$total = $builder->count();

$result = $builder->fields(explode(','), $fields)
    ->sort($sort)
    ->limit($size)
    ->skip($offset)
    ->findAll();