INNER, OUTER OR RIGHT JOIN with 3 tables where one has same PK as the joining one 但 1st doesn't

Question

您好，我目前正在尝试合并 3 种类型的 table。我必须用具有相同值的 2 来做这件事，但是当你想要第 3 个 table 与第二个具有相同但不是第一个的 pk 时会发生什么？我撞到了一堵巨大的砖墙....我该如何解决这个问题？

SELECT xxx.orderid, xxx.ordertime,xxx2.produdct, xxx2.product type, xxx3.priscut xx3.pricename FROM xxx
INNER JOIN xxx2 ON xxx.orderid= xxx2.orderid
RIGHT JOIN xxx3 ON xxx2.productid = xx3.productid;

我最良好的祝愿，迈克

Answer 1

只需使用内连接

SELECT 
 xxx.orderid
, xxx.ordertime
,xxx2.produdct
, xxx2.producttype
, xxx3.priscut xx3.pricename 
FROM xxx
INNER JOIN xxx2 ON xxx.orderid= xxx2.orderid
INNER JOIN xxx3 ON xxx2.productid = xx3.productid;

INNER, OUTER OR RIGHT JOIN with 3 tables where one has same PK as the joining one 但 1st doesn't

INNER, OUTER OR RIGHT JOIN with 3 tables where one has same PK as the joining one but 1st doesn't

mysql

inner-join

right-join