MYSQL - 如何让3行数据变成1行数据

Question

现在我合并 3 个表并选择成为 below show。

|remark|totalA|totalB|tatalC|
-----------------------------
|   a  | 123  | NULL | NULL |

|   a  | NULL | 123  | NULL |

|   a  | NULL | NULL | 123  |

如何让它变成1行如下图？

|remark|totalA|totalB|tatalC|
-----------------------------
|   a  | 123  | 123  | 123  |

我尝试对它进行分组和区分，但它显示在下面

|remark|totalA|totalB|tatalC|
-----------------------------
|   a  | 123  | NULL | NULL |

Answer 1

select 
   remark,
   sum(totalA) as totalA,
   sum(totalB) as totalB,
   sum(totalC) as totalC
from the_table
group by remark