Mysql 多条件查询

Question

我试图进行这样的查询:

$query= "SELECT a.virtuemart_category_id, 
   a.virtuemart_product_id, 
   b.product_name, 
   b.product_desc, 
   c.product_price, 
   d.virtuemart_media_id, 
   e.file_url 
   FROM   wgny6_virtuemart_product_categories a 
   LEFT JOIN wgny6_virtuemart_products_en_gb b 
          ON a.virtuemart_product_id = b.virtuemart_product_id 
   LEFT JOIN wgny6_virtuemart_product_prices c 
          ON b.virtuemart_product_id = c.virtuemart_product_id 
   LEFT JOIN wgny6_virtuemart_product_medias d 
          ON b.virtuemart_product_id = d.virtuemart_product_id 
   LEFT JOIN wgny6_virtuemart_medias e 
          ON d.virtuemart_media_id = e.virtuemart_media_id 
   WHERE  b.product_name IS NOT NULL";

但我希望只有当 a.virtuemart_category_id= $id 时才会发生这种情况。但我不知道如何添加该条件。

Answer 1

简单地添加额外的where条件

 AND a.virtuemart_category_id = $id 

在查询末尾。

即

SELECT a.virtuemart_category_id,a.virtuemart_product_id,b.product_name,b.product_desc, c.product_price,d.virtuemart_media_id,e.file_url 
    FROM wgny6_virtuemart_product_categories a 
      LEFT JOIN wgny6_virtuemart_products_en_gb b ON a.virtuemart_product_id=b.virtuemart_product_id 
      LEFT JOIN  wgny6_virtuemart_product_prices c ON b.virtuemart_product_id=c.virtuemart_product_id 
      LEFT JOIN wgny6_virtuemart_product_medias d ON b.virtuemart_product_id=d.virtuemart_product_id 
      LEFT JOIN wgny6_virtuemart_medias e ON d.virtuemart_media_id=e.virtuemart_media_id 
  WHERE b.product_name IS NOT NULL AND a.virtuemart_category_id = $id