列出所選類別和價格範圍內的產品

Question

我真的很熟悉mysql，不能很好地理解什麼是解決我的問題的正確方法，所以如果有人有線索或解決方案，這是非常值得歡迎的，在這裏我們走。

我在DB兩個表：

產品：

• id_product
• name_product
• 等...

機生產線ct_category：

• id_product
• CATEGORY_NAME

當我保存一個產品和一個以上的類別，它看起來像這樣在我的數據庫：

id_product category_name 
1   kids 
1   men 

在我HTML，我有這樣的一個表格：

<div class="checkbox"> 
    <label><input type="checkbox" class="getcats" value="Women">Women</label> 
</div> 
<div class="checkbox"> 
    <label><input type="checkbox" class="getcats" value="Men">Men</label> 
</div> 
<div class="checkbox"> 
    <label><input type="checkbox" class="getcats" value="Kids">Kids</label> 
</div> 
<div class="form-group" id="range"> 
    € <input type="number" min="0" id="min" name="min" class="form-control" placeholder="0"> 
    € <input type="number" min="0" id="max" name="max" class="form-control" placeholder="100"> 
</div> 
<button class="boton" id="request" onclick="request()">Request</button> 

然後在我的JS文件，我讓Ajax調用：

function request(){ 

    //get the values from price range 
    var min = jQuery("#min").val(); 
    var max = jQuery("#max").val(); 

    //create array to save the selected categories 
    var categories = []; 

    //save all the selected categories into the array 
    jQuery('.getcats').each(function(){ 

    if(jQuery(this).is(":checked")){ 
     categories.push(jQuery(this).val()); 
    } 

    }); 

    jQuery.ajax({ 
     url: 'request.php', 
     method: 'POST', 
     data:{ 
      categories:categories, 
      min:min, 
      max:max 
     }, 
     success: function(data){ 
      //on success, display data requested 
     }, 
     dataType: 'json' 
    }); // End of ajax call 

} 

最後在我的PHP文件：

<?php 
header("Content-type: text/javascript"); 

require_once($_SERVER['DOCUMENT_ROOT'].'/../../config.php'); 
$conn = mysqli_connect($servername, $username, $password, $db); 

//here should be some code to validate price range (min and max) 

//after validation assign to variables 
$min = $_POST["min"]; 
$max = $_POST["max"]; 

//here some code to validate selected categories (checkboxes) 

//after validation assign to variable 

$categories = $_POST["categories"]; 

$categoriesList = implode("','",$Intersectedresult); //$intersectedresult comes from array_intersect($categorias,$checkCategorias) 
$resultList = "'".$categoriasList."'"; 

//Before I had this query working well but only when a product had 1 category, but now each product can have more than 1 category so I don't know how to make that query 
$randomProducts = $conn->query("SELECT * FROM products WHERE category_name IN ($resultList) && product_price BETWEEN $min AND $max ORDER BY rand() LIMIT 3") 

?> 

我研究了一點，發現一些術語，如INNER JOIN，但無法理解如何實現它能夠做到這樣的事情：

$randomProducts = $conn->query("SELECT products.product_name, products.product_image, products.product_desc, products.product_url, products.product_price FROM products INNER JOIN product_category ON product_category.category_name=women, kids or men"); 

希望有人能給我一個推動，非常感謝。

Answer 1

試試這個：

SELECT * 
FROM products p 
WHERE p.id_product IN (
SELECT pc.id_product 
FROM product_category pc 
AND pc.category_name IN ($resultList) 
) 
AND p.product_price BETWEEN $min AND $max ORDER BY rand() LIMIT 3 

Answer 2

您可以使用內部聯接或子查詢概念。 在答案1子查詢被使用，你可以試試這個，.. ..

這是鏈接瞭解內部聯接

http://www.w3schools.com/sql/sql_join_inner.asp

你可以試試這個也

SELECT products.product_name, products.product_image, products.product_desc, products.product_url, products.product_price FROM products INNER JOIN product_category ON table name.table filed=table name.table field （即你要比較大多是兩個表的ID）

Answer 3

在您的查詢中使用GROUP BY id_product

SELECT * 
FROM products 
WHERE category_name 
    IN ($resultList) 
    AND product_price BETWEEN $min AND $max 

GROUP BY id_product 
ORDER BY rand() 
LIMIT 3 

Answer 4

select * 
from product      as PRD 
     inner join product_category as CAT on PRD.id = CAT.id_product 

where CAT.category_name in ('woman', 'kids')