mysql - MySQL Group By 和 Sum 其他列的总值

Question

我有 2 列是这样的：

+----------+--------+
|   word   | amount |
+----------+--------+
| dog      |      1 |
| dog      |      5 |
| elephant |      2 |
+----------+--------+

我想总结金额，得到结果

+----------+--------+
| dog      |      6 |
| elephant |      2 |
+----------+--------+

到目前为止，我尝试过（但失败了）是这样的：

SELECT word, SUM(amount) FROM `Data` Group By 'word'

Answer 1

删除WORD. 它导致列名被转换为字符串。

SELECT word, SUM(amount) 
FROM Data 
Group By word

Answer 2

它应该是重音符号而不是单引号：

SELECT word, SUM( amount )
FROM Data
GROUP BY `word`;

输出：

word     SUM(amount)
dog           6
Elephant      2

Answer 3

SELECT word, SUM(amount) FROM Data Group By word;

Answer 4

试试这种非常规的方法。

SELECT word, SUM(amount) 
FROM Data 
Group By word

Answer 5

SELECT column_name1, SUM(column_name2) 
FROM table_name 
GROUP BY column_name1