如果 else 语句不起作用，laravel 过滤器答案

【问题标题】：laravel filter if else statement is not working如果 else 语句不起作用，laravel 过滤器
【发布时间】：2018-02-06 13:58:38
【问题描述】：

我试图过滤我的产品的价格性别颜色当我使用这样的 url localhost/category/tag?price=100

时，这是我的工作代码

if (request()->has('gender')) {
     $products = Product::withAllTags($tags)->where('gender', request('gender'))->get();
  }
  if (request()->has('price')) {
     $products = Product::withAllTags($tags)->where('price', '<=', request('price'))->get();
  }
  if (request()->has('color')) {
     $products = Product::withAllTags($tags)->whereHas('colors', function ($query) {
          $query->where('name', request('color'));
      })->paginate(20);
  }
  if (request()->has('brand')) {
     $products = Product::withAllTags($tags)->whereHas('brands', function ($query) {
          $query->where('name', request('brand'));
      })->orderBy('created_at', 'desc')->paginate(20);
  }

但是当 url 是 localhost/category/tag 时出现错误

Undefined variable: products

我尝试添加这样的 else 条件

if (request()->has('gender')) {
     $products = Product::withAllTags($tags)->where('gender', request('gender'))->get();
  }
  if (request()->has('price')) {
     $products = Product::withAllTags($tags)->where('price', '<=', request('price'))->get();
  }
  if (request()->has('color')) {
     $products = Product::withAllTags($tags)->whereHas('colors', function ($query) {
          $query->where('name', request('color'));
      })->paginate(20);
  }
  if (request()->has('brand')) {
     $products = Product::withAllTags($tags)->whereHas('brands', function ($query) {
          $query->where('name', request('brand'));
      })->orderBy('created_at', 'desc')->paginate(20);
  }

  else  {
     $products = Product::withAllTags($tags)->orderBy('created_at', 'desc')->paginate(20);
    }

它在 localhost/category/tag 上工作但现在过滤器在 localhost/category/tag?price=100 上不起作用所有数据都显示对不起我的语法

【问题讨论】：

未定义变量在哪一行和哪一页上？
未定义变量：f3407ad99fc10e7e2c6983562937345f02f5bf88.php（第 84 行）中的产品（查看：C:\xampp\htdocs\swimwear2\resources\views\category\index.blade.php）
@GauravRai 未定义变量：f3407ad99fc10e7e2c6983562937345f02f5bf88.php（第 84 行）中的产品（查看：C:\xampp\htdocs\swimwear2\resources\views\category\index.blade.php）
发给你完整的controller方法，用resources\views\category\index.bla‌de.php

标签： php laravel laravel-5.4

【解决方案1】：

你基本上是在做

if (request()->has('brand')) {
     $products = Product::withAllTags($tags)->whereHas('brands', function ($query) {
          $query->where('name', request('brand'));
      })->orderBy('created_at', 'desc')->paginate(20);
  }

  else  {
     $products = Product::withAllTags($tags)->orderBy('created_at', 'desc')->paginate(20);
    }

这使得else 语句适用于request()->has('brand') 将所有条件包装在 if 语句中，将其余条件包装在 else 语句中

if(request()->has('gender')||request()->has('price')||request()->has('color')||request()->has('brand')){
if (request()->has('gender')) {
     $products = Product::withAllTags($tags)->where('gender', request('gender'))->get();
  }
  if (request()->has('price')) {
     $products = Product::withAllTags($tags)->where('price', '<=', request('price'))->get();
  }
  if (request()->has('color')) {
     $products = Product::withAllTags($tags)->whereHas('colors', function ($query) {
          $query->where('name', request('color'));
      })->paginate(20);
  }
  if (request()->has('brand')) {
     $products = Product::withAllTags($tags)->whereHas('brands', function ($query) {
          $query->where('name', request('brand'));
      })->orderBy('created_at', 'desc')->paginate(20);
  }
}
  else  {
     $products = Product::withAllTags($tags)->orderBy('created_at', 'desc')->paginate(20);
    }

【讨论】：