如何使用MySQL从列的所有值中减去相同的值？

首先我们创建一个表 –

mysql> create table DemoTable741 (Number int);
Query OK, 0 rows affected (0.61 sec)

使用插入命令将一些记录插入到表中 –

mysql> insert into DemoTable741 values(70);
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable741 values(55);
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable741 values(89);
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable741 values(79);
Query OK, 1 row affected (0.35 sec)
mysql> insert into DemoTable741 values(34);
Query OK, 1 row affected (0.17 sec)

使用select语句显示表中的所有记录 –

mysql> select *from DemoTable741;

这将产生以下输出 –

+--------+
| Number |
+--------+
| 70     |
| 55     |
| 89     |
| 79     |
| 34     |
+--------+
5 rows in set (0.00 sec)

以下是从列的所有值中减去相同值的查询 –

mysql> select (Number-20) AS Result from DemoTable741;

这将产生以下输出 –

+--------+
| Result |
+--------+
| 50     |
| 35     |
| 69     |
| 59     |
| 14     |
+--------+
5 rows in set (0.00 sec)

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