統計單個項目的行數

Question

我想統計一列中的項目只出現一次的次數。例如，如果在我的表我有...

Name 
---------- 
Fred 
Barney 
Wilma 
Fred 
Betty 
Barney 
Fred 

...這將返回我計數2，因爲只有威爾瑪和貝蒂已經出現過一次。

Answer 1

Here is SQLFiddel Demo

下面是查詢，你可以嘗試：

select count(*) from 
(select Name 
    from Table1 
group by Name 
having count(*) = 1) T 

直到我上面的帖子是您的實際情況後。

---

下面是職位修改問題：

在oracle中，你可以試試下面的查詢：

select sum(count(rownum)) 
    from Table1 
group by "Name" 
having count(*) = 1 

OR

Here is SQLFiddel Demo

---

在SQ l認證服務器，你可以試試下面的查詢：

SELECT COUNT(*) 
    FROM Table1 a 
    LEFT JOIN Table1 b 
    ON a.Name=b.Name 
    AND a.%%physloc%% <> b.%%physloc%% 
WHERE b.Name IS NULL 

OR

Here is the SQLFiddel Demo

---

在Sybase你可以試試下面的查詢：

select count(count(name)) 
    from table 
group by name 
having count(name) = 1 

根據@ user2617962的回答。

謝謝

Answer 2

select count(*) from 
     (select count(*) from Table1 
     group by Name 
     having count(*) =1) s 

SqlFiddle

Answer 3

既然你只需要無柱的實際價值，一旦出現列值的計數，查詢應該是：

select count(count(name)) from table group by name having count(name) 
= 1 

Answer 4

嘗試以下。

select name from (select name, count(name) as num from tblUsers group by name) 
tblTemp where tblTemp.num=1 

馬克它，如果這個工程.. :)