SQL：在多行中选择两列的总和

Question

我有一个像这样的表结构：

-------------------------------------
|  Country  |  Count 1  |  Count 2  |
-------------------------------------
|  USA      |  10       |  10       |
-------------------------------------
|  USA      |  10       |   10      |
-------------------------------------
|  France   |  200      |  200      |
-------------------------------------
|  USA      |  10       |  10       |
-------------------------------------
|  France   |  100      |  100      |
-------------------------------------

我想为每个国家/地区选择计数1和计数2的总和。 所以我的输出就像

-------------------------
|  Country  |  Count    | 
-------------------------
|  USA      |    60     | 
-------------------------
|  France   |   600     |
-------------------------

Answer 1

尝试使用SUM()

SELECT Country,
 SUM(`Count 1` + `Count 2`) AS count
FROM table_name 
GROUP BY country

Answer 2

这非常简单，您可以将聚合函数SUM()与GROUP BY一起使用：

SELECT country, 
  sum(count1 + count2) as Total
FROM yourtable
GROUP BY country;

请参阅Demo

Answer 3

试试这个

SELECT Country, SUM(Count_1 + Count_2)
FROM Table 
GROUP BY Country

Answer 4

试试这个。

UPDATE power 
  SET cnt = SUM(IFNULL(is_yellow, 0) + 
  IFNULL(is_green, 0) +  IFNULL(is_blue, 0));