mysql> drop table if exists foo;
Query OK, 0 rows affected (0.00 sec)

mysql> create table foo (i numeric(23,0) primary key);
Query OK, 0 rows affected (0.01 sec)

mysql> select @@global.sql_mode;
+-------------------+
| @@global.sql_mode |
+-------------------+
|                   | 
+-------------------+
1 row in set (0.00 sec)

mysql> insert into foo values ('a');
Query OK, 1 row affected, 1 warning (0.01 sec)

mysql> set sql_mode='strict_all_tables';
Query OK, 0 rows affected (0.00 sec)

mysql> insert into foo values ('d');
ERROR 1366 (HY000): Incorrect decimal value: 'd' for column 'i' at row 1
mysql>