sql query-＆gt;我将如何从表中获取id

Question

我写了以下查询：

SELECT order_id 
FROM oc_order 
WHERE customer_id=7  
  AND order_status_id=5

这里customer_id 7是硬编码的。而不是硬编码我必须从表中获取id我将如何得到它？

每当客户登录时，表格都会更新

Answer 1

使用Sub-Query

SELECT order_id 
FROM oc_order 
WHERE customer_id=(select customer_id from customer where ..)
  AND order_status_id=5

考虑到您有Customer表，其中存储了新的customer_id

Answer 2

或INNER JOIN

SELECT o.order_id 
FROM oc_order o
INNER JOIN customer c ON c.customer_id = o.customer_id
AND o.order_status_id = 5

Answer 3

试试这个

SELECT order_id
FROM oc_order
WHERE customer_id in (SELECT customer_id 
                      FROM oc_order)
AND order_status_id=5