問(wèn)題描述

我正在開(kāi)發(fā) Laravel 4.據(jù)我所知，我可以做子查詢:

I'm working on Laravel 4. As I knew, I can do subquery:

Project::whereIn('project_id', function($q) {
    $q->select('project_id')
        ->from('company')
        ->whereNull('deleted_at');
});

我發(fā)現(xiàn)了一些復(fù)雜情況，即我無(wú)法在子查詢中使用作用域并禁用 soft_delete 使我對(duì)源代碼進(jìn)行了大量更改.

I found complications, that I can't use scope in subquery and disable soft_delete make me change source code so much.

我希望它是:

Project::whereIn('project_id', function(&$q) {
    $q = Company::select('project_id')->getQuery();
});

現(xiàn)在，我可以添加范圍，輕松禁用 soft_delete.

Now, I can add scope, disable soft_delete easily.

我嘗試并找到了一個(gè)解決方案，即我必須更改 Laravel 的 DatabaseQueryBuilder 代碼，函數(shù) whereInSub，第 786 行.

I tried, and found a solution, that I must change Laravel's DatabaseQueryBuilder code, function whereInSub, line 786.

call_user_func($callback, $query = $this->newQuery());

到:

$query = $this->newQuery();
call_user_func_array($callback, array(&$query));

修改 Laravel 框架的供應(yīng)商是有害的.所以想問(wèn)一下怎么安全的做.

It's harmful to modify Laravel framework's vendor. So I want to ask how to do it safely.

對(duì)不起，因?yàn)槲业挠⒄Z(yǔ)不好.

Sorry because my bad English.

感謝您的閱讀.

推薦答案

哦！這是一個(gè)相當(dāng)棘手的問(wèn)題，因?yàn)槟哪Ｐ蛯U(kuò)展 Eloquent，然后 Eloquent 使用 IlluminateDatabaseQueryBuilder.

Oooh! This is quite a tricky one since your model would extend Eloquent, then Eloquent uses IlluminateDatabaseQueryBuilder.

但我注意到 Eloquent 實(shí)際上是 app/config/app.php 文件中的別名.因此，您可以執(zhí)行以下步驟.

But what I noticed is that Eloquent is actually an alias in app/config/app.php file. So what you can do is following these steps.

1. 使用自定義的 whereInSub() 將 IlluminateDatabaseQueryBuilder 擴(kuò)展到 MyQueryBuilder.
2. 將 IlluminateDatabaseEloquentModel 擴(kuò)展到 MyModel 并使其 use 你的 MyQueryBuilder.
3. 將 app/config/app.php 中的 Eloquent 別名設(shè)置為新的 MyModel 類.

1. Extend IlluminateDatabaseQueryBuilder to MyQueryBuilder with your custom whereInSub().
2. Extend IlluminateDatabaseEloquentModel to MyModel and make it use your MyQueryBuilder.
3. Set Eloquent alias in app/config/app.php to your new MyModel class.

像這樣:

MyQueryBuilder.php:

use Closure;
use IlluminateSupportCollection;
use IlluminateDatabaseConnectionInterface;
use IlluminateDatabaseQueryGrammarsGrammar;
use IlluminateDatabaseQueryProcessorsProcessor;

class MyQueryBuilder extends IlluminateDatabaseQueryBuilder
{
    protected function whereInSub($column, Closure $callback, $boolean, $not)
    {
        $type = $not ? 'NotInSub' : 'InSub';

        $query = $this->newQuery(); // Your changes
        call_user_func_array($callback, array(&$query)); // Your changes

        $this->wheres[] = compact('type', 'column', 'query', 'boolean');

        $this->mergeBindings($query);

        return $this;
    }
}

MyModel.php:

use DateTime;
use ArrayAccess;
use CarbonCarbon;
use LogicException;
use IlluminateEventsDispatcher;
use IlluminateDatabaseEloquentRelationsPivot;
use IlluminateDatabaseEloquentRelationsHasOne;
use IlluminateDatabaseEloquentRelationsHasMany;
use IlluminateDatabaseEloquentRelationsMorphTo;
use IlluminateSupportContractsJsonableInterface;
use IlluminateSupportContractsArrayableInterface;
use IlluminateDatabaseEloquentRelationsRelation;
use IlluminateDatabaseEloquentRelationsMorphOne;
use IlluminateDatabaseEloquentRelationsMorphMany;
use IlluminateDatabaseEloquentRelationsBelongsTo;
// use IlluminateDatabaseQueryBuilder as QueryBuilder;
use IlluminateDatabaseEloquentRelationsMorphToMany;
use IlluminateDatabaseEloquentRelationsBelongsToMany;
use IlluminateDatabaseEloquentRelationsHasManyThrough;
use IlluminateDatabaseConnectionResolverInterface as Resolver;
use MyQueryBuilder as QueryBuilder; // MyModel should now use your MyQueryBuilder instead of the default which I commented out above

abstract class MyModel extends IlluminateDatabaseEloquentModel
{

}

app/config/app.php:

'aliases' => array(
    ...
    'Eloquent'        => 'MyModel',
    ...
);

請(qǐng)注意，我將一長(zhǎng)串 use 放在那里，因?yàn)?"use" 關(guān)鍵字不會(huì)被繼承.此外，為了簡(jiǎn)單起見(jiàn)，我沒(méi)有將 MyQueryBuilder 和 MyModel 放在命名空間中.根據(jù)我們使用的 Laravel 版本，我的 use 列表也可能與您的不同，因此請(qǐng)檢查用途.

Note that I put long lists of use up there because "use" keyword does not get inherited. Also I did not put MyQueryBuilder and MyModel in a namespace for the sake of simplicity. My use list might also be different from yours depending on Laravel versions we use, so please check the uses too.

這篇關(guān)于如何自定義 Laravel 的 DatabaseQueryBuilder(制作更好的子查詢)的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！