Opencart过滤器模块查询语句，价格和特殊价格范围

Question

感谢您停止我的问题:)

我正在为我的网上商店开发一个Opencart过滤器模块，但是遇到了一个MySql查询，有点麻烦了。

该脚本的目的是通过给定的过滤器凭据返回找到的产品数量：

• 最低价格
• 最高价
• 类别编号
• 制造商编号

我遇到的问题是在设置最低/最高价格时，如何获得正确的产品计数。 这是因为某些产品正在销售中。 这意味着它应该检查价格是否在特价范围内，而不是正常价格范围内。

• 特价列为“ ps.price”

• 产品价格为“ p.price”

   $query = $this->db->query("SELECT *, count(p.product_id) as count FROM " . DB_PREFIX . "manufacturer m LEFT JOIN " . DB_PREFIX . "manufacturer_to_store m2s ON (m.manufacturer_id = m2s.manufacturer_id) LEFT JOIN " . DB_PREFIX . "product p ON (m.manufacturer_id = p.manufacturer_id) LEFT JOIN " . DB_PREFIX . "product_to_category p2c ON (p2c.product_id = p.product_id) LEFT JOIN " . DB_PREFIX . "product_special ps ON (ps.product_id = p.product_id) WHERE m2s.store_id = '" . (int)$this->config->get('config_store_id') . "' AND m.manufacturer_id = '" . $manufacturer_id . "' AND (ps.price BETWEEN '" . $min_price . "' AND '" . $max_price . "') AND (p.price BETWEEN '" . $min_price . "' AND '" . $max_price . "') AND p.status = 1 "); $manufacturer_data = $query->rows; 

我需要的是，如果不为null，则只能从ps.price中进行选择，否则从p.price列中进行选择

提前致谢 ：）

Answer 1

试试这个查询...

$query = $this->db->query("
    SELECT *, CASE WHEN ps.price IS NULL THEN p.price ELSE ps.price END product_price
    FROM " . DB_PREFIX . "manufacturer m 
        LEFT JOIN " . DB_PREFIX . "manufacturer_to_store m2s ON (m.manufacturer_id = m2s.manufacturer_id) 
        LEFT JOIN " . DB_PREFIX . "product p ON (m.manufacturer_id = p.manufacturer_id) 
        LEFT JOIN " . DB_PREFIX . "product_special ps ON (ps.product_id = p.product_id)
    WHERE m2s.store_id = '" . (int)$this->config->get('config_store_id') . "' 
        AND m.manufacturer_id = '" . $manufacturer_id . "'
        AND (product_price BETWEEN '" . $min_price . "' AND '" . $max_price . "') 
        AND p.status = 1
");