Integer types can handle positive and negative numbers, but if the data type is followed by UNSIGNED, only 0 and positive numbers can be stored. Such data types are called unsigned integer types. For example, to make INT type unsigned, write as follows.
mysql> create table numtest(
-> num1 smallint unsigned
-> );
Query OK, 0 rows affected (0.17 sec)
mysql> insert into numtest values(5000);
Query OK, 1 row affected (0.12 sec)
mysql> insert into numtest values(-10);
Query OK, 1 row affected, 1 warning (0.03 sec)
mysql> select * from numtest;
+——+
| num1 |
+——+
| 5000 |
| 0 |
+——+
2 rows in set (0.00 sec)
