如何使用MySQL从一列的所有值中减去相同的金额?
让我们首先创建一个表-
create table DemoTable741 (Number int);
使用插入命令在表中插入一些记录-
insert into DemoTable741 values(70); insert into DemoTable741 values(55); insert into DemoTable741 values(89); insert into DemoTable741 values(79); insert into DemoTable741 values(34);
使用select语句显示表中的所有记录-
select *from DemoTable741;
这将产生以下输出-
+--------+ | Number | +--------+ | 70 | | 55 | | 89 | | 79 | | 34 | +--------+ 5 rows in set (0.00 sec)
以下是从列中的所有值中减去相同金额的查询-
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)