Question

我仍在尝试连接表，但是当我尝试运行它时，它无法正常运行。此外，输入的底部块搞砸了。我希望输出显示代表值1-10。任何帮助将不胜感激。

SELECT customer_id, cust_first_name
FROM demo_customers
WHERE cust_state= 'VA'
INNER JOIN demo_orders
ON demo_customers.customer_id.cust_first_name=demo_orders.order_id


SELECT order_id
FROM demo_orders
WHERE customer_id= '1'

SELECT order_item_id
FROM demo_order_items
WHERE order_id= '2'

SELECT product_name
FROM demo_product_info
WHERE product_id= <10

Answer 1

demo_customers.customer_id.cust_first_name = demo_orders.order_id

应该阅读

demo_customers.customer_id = demo_orders.order_id

Answer 2

这里的内容并不完全清楚，但是这样的话会在4个桌子上提供连接。

SELECT 
   *
FROM 
   demo_customers
INNER JOIN demo_orders
   ON demo_customers.customer_id=demo_orders.customer_id
INNER JOIN demo_order_items
   ON demo_order.order_id = demo_order_items.order_id
INNER JOIN demo_product_info
   ON demo_product_info.product_id = demo_order_item.product_id
WHERE 
  cust_state= 'VA'

Answer 3

试试这个

  SELECT demo_customers.customer_id, demo_customers.cust_first_name
    FROM demo_customers c
      INNER JOIN demo_orders o
    ON demo_customers.customer_id = demo_orders.order_id
       WHERE c.cust_state= 'VA';

加入SQL表并更新值

3 个答案: