Question

我有以下疑问：

Select TRUNC(create_dtime) as Day, Count(Create_Dtime) As SinS_Tot
  From player_chkin_hist
 Where Product_Id Is Not Null
   And Trunc(Create_Dtime) >= To_Date('2012-sep-01','yyyy-mon-dd')
   And Trunc(Create_Dtime) < To_Date('2012-sep-19','yyyy-mon-dd')
 Group By Trunc(Create_Dtime)
 Order By 1 Asc

和

Select TRUNC(Create_Dtime) As Day, Count(Create_Dtime) As Sins_Tot
  From Player_Chkin
 where Product_Id Is Not Null
   And Trunc(Create_Dtime) >= To_Date('2012-sep-01','yyyy-mon-dd')
   And Trunc(Create_Dtime) < To_Date('2012-sep-19','yyyy-mon-dd')
 Group By Trunc(Create_Dtime)
 Order By 1 Asc

查询1结果：

Day          SinS_Tot
01-Sep-12      10000
02-Sep-12       9000

查询两个结果：

 Day          SinS_Tot
03-Sep-12      11500
04-Sep-12       9800

有没有一种简单的方法来组合这两个查询，以便我看到所有数据？我想过使用连接，但由于日期不重叠，所以没有什么可以设置内部连接相等。

Answer 1

您要找的是UNION（或UNION ALL，具体取决于您是否要删除重复项：）

Select 
trunc(create_dtime) as Day, Count(Create_Dtime) As SinS_Tot
From player_chkin_hist
Where
Product_Id Is Not Null And
Trunc(Create_Dtime) >= To_Date('2012-sep-01','yyyy-mon-dd')
And Trunc(Create_Dtime) < To_Date('2012-sep-19','yyyy-mon-dd')
Group By Trunc(Create_Dtime)

UNION

Select Trunc(Create_Dtime) As Day, Count(Create_Dtime) As Sins_Tot
From Player_Chkin
where
Product_Id Is Not Null And
Trunc(Create_Dtime) >= To_Date('2012-sep-01','yyyy-mon-dd')
And Trunc(Create_Dtime) < To_Date('2012-sep-19','yyyy-mon-dd')
Group By Trunc(Create_Dtime)
Order By 1 Asc

Answer 2

你可以UNION ALL两个结果

<<query 1>>
UNION ALL
<<query 2>>

您也可以使用UNION，但这会更昂贵，因为它会强制Oracle查找并消除重复的行。如果你知道这两个查询永远不会返回同一行，或者你想要两个行，那么这是不必要的开销。

Answer 3

他们之间可能有一个UNION吗？将ORDER BY保留在查询之外，将其放在第二个

的末尾

Query1
 UNION
Query2

Answer 4

您只需要使用UNION组操作符。

[查询1] UNION ALL [QUERY2]

SQL Oracle-将两个结果集合并为一个

4 个答案: