Question

我是mysql的新手，并且不能很好地理解解决我的问题的正确方法，所以如果有人有线索或解决方案，那么我们非常欢迎。

我的数据库中有两个表：

产品：

id_product
name_product
等...

PRODUCT_CATEGORY：

id_product
CATEGORY_NAME

当我保存具有多个类别的产品时，它在我的数据库中显示如下：

id_product  category_name
1           kids
1           men

在我的HTML中，我有一个这样的表单：

<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>

然后在我的JS文件中进行ajax调用：

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 

}

最后在我的php文件中：

<?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")

?>

我正在研究一下，发现了一些术语，比如INNER JOIN，但是不能理解如何实现它，以便能够做到这样的事情：

$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");

希望有人能给我一个推动，非常感谢。

Answer 1

试试这个：

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

您可以使用内部联接或子查询概念。在回答1中使用了子查询，您可以尝试这个，..

这是了解内部联接的链接

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

你也可以尝试这个

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 （你要比较它主要是两张桌子的id）

Answer 3

在您的查询GROUP BY id_product

中使用

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')

列出所选类别和价格范围

4 个答案: