Oracle - 计算列的不同值
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Oracle - Count distinct values of a column
提问by Luciana Borela
I have this table:
我有这张表：
Reason|Area_Code|Id
x dig 1
x dig 2
y dig 3
h util 4
x dig 5
I'm trying for a SQL that returns:
我正在尝试一个返回的 SQL：
Reason|Amount of distinct Reason|Area_code
x 3 dig
y 1 dig
h 1 util
I will use this result to plot a chart. I don′t have any idea on how this SQL can be done. Could you help me?
我将使用此结果绘制图表。我不知道如何完成此 SQL。你可以帮帮我吗？
回答by Charles Bretana
Try This:
尝试这个：
Select Reason, Count(*) AmountOfReason, Area_Code
From Table
Group By Reason, Area_Code
... but this assumes that Area_Code is always determined by Reason, i.e., they are always paired, that you do not have 2 rows in yr table like
...但这假设 Area_Code 始终由 Reason 确定，即，它们始终成对，您在 yr 表中没有 2 行，例如
x util 5
x dig 6
cause if that was the case this won't work.
因为如果是这样的话，这将不起作用。
