mysql从两个表中获取具有单一陈述的数据

Question

表格用户

usrid names country city
------------------------

1    john doe   uk   landon   
2    jane deo   uk   landon

表味精

msg_id msg_from msg_to
----------------------


1      ID 1      ID 2

现在-示例

msg_id msg_from                                                         msg_to
----------------------


1      ID 1 from tbl USERS - get names for this ID from table users     ID 2 from tbl USERS - get names for this ID from table users

我如何通过从表msg中进行选择来获取名称以及如何使用单个mysql语句从表用户中获取名称 就像加入

Answer 1

所以JOIN的工作方式如下：

SELECT msg_id, msgfrom.name AS msg_from, msgto.name AS msg_to
FROM MSG
JOIN USERS msgfrom ON msg_from = msgfrom.usrid
JOIN USERS msgto ON msg_to = msgto.usrid