使用 Laravel 通过标准从数据库中提取数据

Question

您好，我尝试编写一些查询，希望通过相关标准从帐户中提取电子邮件。因此，例如，如果我想按城市发送电子邮件，我可以选择城市并将电子邮件发送给这个城市的人，但如果我不选择任何城市，它不应该识别这个并发送给所有人。

我的问题有没有按标准从数据库中提取数据的最佳方法？我应该写一个查询还是最好的方法是什么？

Answer 1

我不知道你到底在做什么，但基于对 Laravel 的基本了解以及你试图用不同的“标志”或“标准”做什么，继续添加是否有意义根据每个条件到主集合，然后在主集合的查询属性全部添加后获取电子邮件地址。例如：

// Start with your Account, ordered by ID:

$accounts = Account::orderBy('id');

// if a city ID is provided, add this to the "where" section of the main collection:

if($this->city_id !== NULL) {
    $accounts->where('location_id', $this->city_id);
}

// if an Account Type is provided, add this to the "where" section of the main collection:

if ($this->account_type !== NULL) {
    $accounts->where('type_id', $this->account_type);
}

// if Premium Only is set, add this to the "where" section of the main collection:
if ($this->only_premium == TRUE) {
    $accounts->where('is_premium', $this->only_premium);
}

// if Free Only is set, add this to the "where" section of the main collection:

if ($this->only_free == TRUE) {
    $accounts->where('is_premium', $this->only_free);
}

/* For those last two, it's a bit confusing whether only_free and     only_premium are mutually exclusive, 
 so maybe consider having one property that toggles between Free/Premium 
(assuming it can't be both but must be one or the other). */

// Finally, pull the emails (the "plucking" off of the final $accounts collection variable:

    $emailAccounts = $accounts->get()->pluck('email')->toArray();

我相当肯定，这个示例代码的至少一部分从根本上是错误的，但从根本上说，它对于您想要做的事情也更加合乎逻辑和清晰。