Question

有customer表：

---+-------+------------+
id + name  + region     + 
---+-------+------------+

还有orders表：

---+--------------+------------+----------+----------------+
id + cusomer_id   + product    +  price   +  amount_total  +
---+--------------+------------+----------+----------------+

如果我想列出每个客户曾经购买过的产品列表，请在';'一行，我提出了一个请求：

            SELECT GROUP_CONCAT(orders.product separator ';') 
            FROM orders
            WHERE orders.customer_id = customer.id

一切正常，但是，如果我想添加一些过滤器，则会出现错误：

SELECT customers.id, 
      (SELECT GROUP_CONCAT(orders.product separator ';') 
       FROM orders
       WHERE orders.customer_id = customers.id) as products 
FROM  customers        
WHERE customers.region like 'USA' 
      AND products not like '%fish%'


Query Error: Error: ER_BAD_FIELD_ERROR: Unknown column 'products' in 'where clause'

db-fiddle.com

Answer 1

如果它不是您的数据库列，则不能使用products来完成它

SELECT customers.id, 
      (SELECT GROUP_CONCAT(orders.product separator ';') 
       FROM orders
       WHERE orders.customer_id = customers.id) as products 
FROM  customers        
WHERE customers.region like 'USA' 
      AND (SELECT GROUP_CONCAT(orders.product separator ';') 
       FROM orders
       WHERE orders.customer_id = customers.id) not like '%fish%'

如何使用特殊产品的订单过滤行？

1 个答案: