Question

您好我试着写一些查询，我想根据相关标准从帐户中提取电子邮件。因此，例如，如果我想通过城市发送电子邮件，我可以选择城市并发送电子邮件给这个城市的人，但如果我不选择任何城市，它不应该认识到这一点，并发送给所有人。

我的问题是否有从标准中提取数据的最佳方法？我应该写一个查询或者最好的方法是什么？

Answer 1

我不知道你在做什么，但基于对Laravel的基本理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();

我相当确定这个示例代码中至少有一部分是根本错误的，但是对于你想要做的事情来说，它也从根本上更符合逻辑和清晰。

使用Laravel按标准从数据库中提取数据

1 个答案: