Let us first create a table −
mysql> create table DemoTable741 (Number int); Query OK, 0 rows affected (0.61 sec)
Insert some records in the table using insert command −
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)
Display all records from the table using select statement −
mysql> select *from DemoTable741;
This will produce the following output -
+--------+ | Number | +--------+ | 70 | | 55 | | 89 | | 79 | | 34 | +--------+ 5 rows in set (0.00 sec)
Following is the query to subtract the same amount from all the values in a column −
mysql> select (Number-20) AS Result from DemoTable741;
This will produce the following output -
+--------+ | Result | +--------+ | 50 | | 35 | | 69 | | 59 | | 14 | +--------+ 5 rows in set (0.00 sec)