使用MySQL从另一列中相应的重复值添加记录

为此，可以使用聚合函数SUM()和GROUP BY子句。让我们首先创建一个表 –

mysql> create table DemoTable
   -> (
   -> Name varchar(20),
   -> Value int
   -> );
Query OK, 0 rows affected (2.08 sec)

使用插入命令在表中插入一些记录 –

mysql> insert into DemoTable values('Chris',50);
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable values('David',90);
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable values('Chris',60);
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable values('Bob',100);
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable values('David',80);
Query OK, 1 row affected (0.21 sec)

使用select语句显示表中的所有记录 –

mysql> select * from DemoTable;

这将产生以下输出 –

+-------+-------+
| Name  | Value |
+-------+-------+
| Chris | 50    |
| David | 90    |
| Chris | 60    |
| Bob   | 100   |
| David | 80    |
+-------+-------+
5 rows in set (0.00 sec)

以下是从另外一列的重复值添加记录的查询 –

mysql> select Name,sum(Value) as GrandTotal from DemoTable group by Name;

这将产生以下输出 –

+-------+------------+
| Name  | GrandTotal |
+-------+------------+
| Chris |        110 |
| David |        170 |
| Bob   |        100 |
+-------+------------+
3 rows in set (0.03 sec)