Question

我在我的产品页面中展示了类似的产品。我有一个查询，查找所有正在查看的产品具有类似brand_id或cat_id的产品。我的问题是它还显示了在类似部分中查看的当前产品。我需要这样做，以便删除从类似产品部分查看的当前产品。

这是我现在的查询。（'id'，'！=='，$ product-＆gt; id部分无效）

    /**
     * Show a Product in detail
     *
     * @param $product_name
     * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
     */
    public function show($product_name) {

        // Find the product by the product name in URL
        $product = Product::ProductLocatedAt($product_name);

        // Select All from "products" table where the brand_id is = to the current product being viewed with its brand_id, OR where
        // the category_id is = to the current product category Id being viewed. This is so we can display similar products for a           // particular product being shown.
        $similar_product = Product::where('brand_id', '=', $product->brand_id)
                 ->where('id', '!==', $product->id)
                 ->orWhere('cat_id', '=', $product->cat_id)->get();

        return view('pages.show_product', compact('product', 'similar_product'));
    }

********编辑******** 我在使用您的查询方法时得到了这个：

你知道那可能吗？

Answer 1

使用OR时请记住，Laravel的查询构建器默认情况下不添加括号。

https://laravel.com/docs/5.2/queries

您的查询最终会如下：

SELECT *
FROM products
WHERE brand_id = 1
   AND id != 2
   OR cat_id = 3

由于OR，结果包括基于其cat_id的产品。

你可能想要的是：

$similar_product = Product::where('id', '!=', $product->id)
    ->where(function ($query) use ($product) {
        $query->where('brand_id', '=', $product->brand_id)
            ->orWhere('cat_id', '=', $product->cat_id);
    })->get();

这会将OR部分放在一组括号内：

SELECT *
FROM products
WHERE id != 2
   AND (brand_id = 1 OR cat_id = 3)

请记住，MySQL通常在优化OR子句方面做得不好。如果您的表很大，您可能需要仔细检查性能和索引使用情况。

Answer 2

您是否尝试将！==更改为＆lt;＆gt;？

    /**
 * Show a Product in detail
 *
 * @param $product_name
 * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
 */
public function show($product_name) {

    // Find the product by the product name in URL
    $product = Product::ProductLocatedAt($product_name);

    // Select All from "products" table where the brand_id is = to the current product being viewed with its brand_id, OR where
    // the category_id is = to the current product category Id being viewed. This is so we can display similar products for a           // particular product being shown.
    $similar_product = Product::where('brand_id', '=', $product->brand_id)
             ->where('id', '<>', $product->id) // changed this line..
             ->orWhere('cat_id', '=', $product->cat_id)->get();

    return view('pages.show_product', compact('product', 'similar_product'));
}

！==不是MySQL的正确语法。

Answer 3

我认为它不起作用，因为逻辑上你说的是

Brand ID equals AND product is not the same OR category equals

由于如果类别匹配，则没有定义优先级，该子句将为整个where语句返回true

您需要弄清楚如何对其进行分组，以便您的查询优先级如下

(ID is not the same) AND (brand matches OR category matches)

其中ID不等于正在查看的当前产品ID - Laravel 5.2

3 个答案: