如何在 Laravel 中对自定义查询的结果进行分块

问题描述

我有一个自定义查询，它从旧系统中获取数据并将其映射到新系统中的模型.查询如下所示:

I have a custom query that grabs data from the old system and maps it to models in the new system. The query looks like this:

$companies = DB::connection('legacy')->select("...");

由于数据量很大，我想使用 Eloquent 的块功能(只是从他们的文档中复制的示例代码):

And since it's a lot of data, I'd like to use Eloquent's chunk feature (just sample code copied from their docs):

User::chunk(200, function($users)
{
    foreach ($users as $user)
    {
        //
    }
});

我该如何实施?

我的代码现在看起来像这样，导致没有响应:

My code now looks like this, which results in no response:

DB::connection('legacy')->select("SELECT * FROM companies")->chunk(200, function($companies) {
    foreach ($companies as $company) {
        // dd($company);
        $entity       = Entity::firstOrNew(['external_id' => $company->companyKey]);
        $entity->name = $company->companyName;
        $entity->save();
    }
});

推荐答案

试试这个:

<?php

$max = 100;
$total = DB::connection('legacy')->select("...")->count();
$pages = ceil($total / $max);
for ($i = 1; $i < ($pages + 1); $i++) {
    $offset = (($i - 1)  * $max);
    $start = ($offset == 0 ? 0 : ($offset + 1));
    $legacy = DB::connection('legacy')->select("...")->skip($start)->take($max)->get();
    /* Do stuff. */
}

基本上复制了 Laravel 的分页器所做的事情，而没有额外的开销.

Basically duplicates what Laravel's Paginator does without the extra overhead.

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