Let us first create a demo table
mysql> create table RandomNumberDemo -> ( -> MyNumber int -> ); Query OK, 0 rows affected (0.54 sec)
Insert some records in the table using insert command. The query is as follows −
mysql> insert into RandomNumberDemo values(17); Query OK, 1 row affected (0.20 sec) mysql> insert into RandomNumberDemo values(18); Query OK, 1 row affected (0.12 sec) mysql> insert into RandomNumberDemo values(29); Query OK, 1 row affected (0.49 sec)
Display all records from the table using select statement. The query is as follows −
mysql> select *from RandomNumberDemo;
The following is the output
+----------+ | MyNumber | +----------+ | 17 | | 18 | | 29 | +----------+ 3 rows in set (0.00 sec)
Here is the query to add a random number between 30 and 300 to an existing field
mysql> update RandomNumberDemo set MyNumber=MyNumber+ FLOOR(RAND() * (270 + 1)) + 30 where MyNumber=18; Query OK, 1 row affected (0.20 sec) Rows matched: 1 Changed: 1 Warnings: 0
Let us check the table records once again. The query is as follows −
mysql> select *from RandomNumberDemo;
The following is the output
+----------+ | MyNumber | +----------+ | 17 | | 158 | | 29 | +----------+ 3 rows in set (0.00 sec)