SQL COUNT國籍與多位藝術家和藝術家的數量，國籍

Question

藝術家

（名字，姓氏，國籍）

Miro      Joan      Spanish      
Kandinsky     Wassily      Russian      
Klee      Paul      German       
Matisse      Henri      French       
Chagall      Marc      French       
Sargent      John Singer     United States     
Tobey      Mark      United States     
Horiuchi     Paul      United States     
Graves      Morris      United States     
Julio      Bloxham Smythe    Spanish      
Basher      Bigmouth     Spanish  

我必須列出所有的民族與代表多位藝術家在數據庫中，和國籍的藝術家的數量

所以輸出應該是

Spanish   3 
United states 4 
French   2 

Answer 1

HAVING是你的朋友

SELECT NATIONALITY, COUNT(*) 
FROM ARTIST 
GROUP BY NATIONALITY 
HAVING COUNT(*)>1 

Answer 2

select nationality, 
     count(firstname) as artists -- counts the artists 
from mytable 
group by nationality -- we group on this, because we want to aggregate the other info 
having count(firstname) >1 -- applies a condition AFTER the count 

Answer 3

你可以使用一個group by條款適用每國籍一組，然後having條款只保留民族與多位藝術家：

SELECT nationality, COUNT(*) 
FROM  artist 
GROUP BY nationality 
HAVING COUNT(*) > 1 

Answer 4

使用分組方式

SELECT count(*),`NATIONALITY` 
FROM `ARTIST` 
GROUP BY `NATIONALITY` 
HAVING count(FIRSTNAME) > 1 

Answer 5

使用具有是沒有必要的，簡單的GROUP BY會做：

SELECT NATIONALITY,COUNT(*) FROM ARTIST GROUP BY NATIONALITY; 

Answer 6

你需要使用什麼是計數功能。嘗試https://www.tutorialspoint.com/sql/sql-count-function.htm

我認爲你需要的是一個普遍的計數。它是如此簡單：

Count(*) 

我想這個問題已被問過很多次，所以爲了節省時間下次嘗試搜索文檔。