mysql> CREATE TABLE TB1(    -> username VARCAHR(20),    -> age TINYINT UNSIGNED,    -> salary FLOAT(8,2) UNSIGNED    -> );ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'VARCAHR(20),age TINYINT UNSIGNED,salary FLOAT(8,2) UNSIGNED)' at line 2怎么解决，实在没辙了