SQL-Join 2查询？

我有两个问题：

Select trunc(create_dtime) as Day, Count(Player_Id) as New_Users
From Player
Where Trunc(Create_Dtime) >= To_Date('2012-Jan-01','yyyy-mon-dd')
Group By Trunc(Create_Dtime)

及

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每天都有一个值，我希望将这两个查询连接在一起，因此我只有一个查询而不是两个查询。

这只是一个内部连接，除非您希望在另一个查询中包含不匹配的结果。否则，您只需使用：

SELECT * FROM query1 INNER JOIN query2 ON query1.Day=query2.Day

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我应该注意到这是MySQL的语法，我不知道你把它标记为Oracle。语法可能会相似，如果不完全相同的话，但我从未使用过Oracle。

我知道了，只是忘了给列添加标签

Select one.Day, one.New_Users, two.Retained_Users
From
(
Select trunc(create_dtime) as Day, Count(Player_Id) as New_Users
From Player
Where Trunc(Create_Dtime) >= To_Date('2012-Jan-01','yyyy-mon-dd')
Group By Trunc(Create_Dtime)
) One
Inner Join 
(
Select trunc(create_dtime) as Day,Count(Player_Id) as Retained_Users
From Player
Where Trunc(Create_Dtime) >= To_Date('2012-Jan-01','yyyy-mon-dd')
And Trunc(Init_Dtime)  >= Trunc(Sysdate) - 7
Group By Trunc(Create_Dtime)
Order By Day Asc
) Two On One.Day=Two.Day
Order By 1

---

您不需要在那里加入：

SELECT
  TRUNC(CREATE_DTIME) AS DAY,
  COUNT(PLAYER_ID) AS NEW_USERS,
  COUNT(CASE WHEN TRUNC(INIT_DTIME) >= TRUNC(SYSDATE) - 7 THEN PLAYER_ID ELSE NULL END)     AS RETAINED_USERS
FROM PLAYER
WHERE TRUNC(CREATE_DTIME) >= TO_DATE('2012-Jan-01','yyyy-mon-dd')
GROUP BY TRUNC(CREATE_DTIME)
ORDER BY 1

---

为了得到您想要的结果集，您尝试了什么查询？表的结构是什么？要回答您的问题，您应该向我们展示您想要的是什么，然后查询一中有几天没有出现在查询二中，反之亦然。很抱歉，问题/答案不是很清楚。我想我已经处理好了。请你再投票好吗？

SELECT
  TRUNC(CREATE_DTIME) AS DAY,
  COUNT(PLAYER_ID) AS NEW_USERS,
  COUNT(CASE WHEN TRUNC(INIT_DTIME) >= TRUNC(SYSDATE) - 7 THEN PLAYER_ID ELSE NULL END)     AS RETAINED_USERS
FROM PLAYER
WHERE TRUNC(CREATE_DTIME) >= TO_DATE('2012-Jan-01','yyyy-mon-dd')
GROUP BY TRUNC(CREATE_DTIME)
ORDER BY 1