SQL连接两个以上的表

Question

我有4张桌子：

• 销售
• 产品
• vender_info
• 商贩

问题是：卖方和客户不同的product_id的显示列表。

请解决这个问题。

tables

Answer 1

不确定你会对这些数据做什么，但这是查询：

SELECT vp.PRODUCT_ID, vv.VENDERS, vs.CUSTOMERNAME
FROM vna_sales vs
JOIN vna_products vp ON vs.ORDERID = vp.ORDERID
JOIN vna_venders vv ON vp.VENDER_ID = vv.VENDER_ID 
WHERE vv.VENDERS <> vs.CUSTOMERNAME

Answer 2

请试试这个

SELECT * 
    FROM vna_shipments a
    inner join vna_parts b on a.id = b.id //some joing factor
    inner vna_suppliers c on a.id = c.id   //some joing factor
    inner vna_projects d on a.id = d.id  //some joing factor

    group by vendor_id, customer_id
    order by vendor_id desc