Mysql 连接两个sql表

我有两个包含数据的表：

GroupMembers
Users, GroupID

GroupPosts
GroupID,PostID

我想得到一个包含

Users, GroupID, PostID

+-------+--------+-------+
| User  | Group  | Post  |
+-------+--------+-------+
| User1 | Group1 | Post1 |
+-------+--------+-------+
| User1 | Group1 | Post2 |
+-------+--------+-------+
| User2 | Group1 | Post1 |
+-------+--------+-------+
| User2 | Group1 | Post2 |
+-------+--------+-------+
| User2 | Group2 | Post1 |
+-------+--------+-------+
| User2 | Group2 | Post4 |
+-------+--------+-------+
| User3 | Group2 | Post1 |
+-------+--------+-------+
| User3 | Group2 | Post4 |
+-------+--------+-------+

用户可以属于多个组，每个组可以有多个帖子。所以我希望所有的用户和每一篇文章

所以如果

GroupMembers:

+-------+---------+
| Users | GroupID |
+-------+---------+
| User1 | Group1  |
+-------+---------+
| User2 | Group1  |
+-------+---------+
| User2 | Group2  |
+-------+---------+
| User3 | Group2  |
+-------+---------+

GroupPosts

+---------+--------+
| GroupID | PostID |
+---------+--------+
| Group1  | Post1  |
+---------+--------+
| Group1  | Post2  |
+---------+--------+
| Group2  | Post1  |
+---------+--------+
| Group2  | Post4  |
+---------+--------+

应该返回一个包含

Users, GroupID, PostID

+-------+--------+-------+
| User  | Group  | Post  |
+-------+--------+-------+
| User1 | Group1 | Post1 |
+-------+--------+-------+
| User1 | Group1 | Post2 |
+-------+--------+-------+
| User2 | Group1 | Post1 |
+-------+--------+-------+
| User2 | Group1 | Post2 |
+-------+--------+-------+
| User2 | Group2 | Post1 |
+-------+--------+-------+
| User2 | Group2 | Post4 |
+-------+--------+-------+
| User3 | Group2 | Post1 |
+-------+--------+-------+
| User3 | Group2 | Post4 |
+-------+--------+-------+

我希望这有意义

---

谢谢你的帮助

您可以使用一个简单的

JOIN

查询，例如：

SELECT g.users, g.groupID, gp.postid
FROM GroupMembers g JOIN GroupPosts gp ON g.groupID = gp.groupID;

---

人们喜欢使用JOIN语法，您可能也喜欢，但我发现使用equals“oldschool”语法更容易阅读：

---

使用JOIN只需要在b.GroupID=a.GroupID上使用JOIN，我相信。：）

选择m.users、m.groupid、p.groupid、p.postid

来自作为m的GroupMembers

在m.groupid=p.groupid上以p的身份加入GroupPost

在手机上，所以不能回头看你的帖子，但我想就是这样