Help with query error

Can’t seem to be able to see what’s wrong with this query. Could a kind soul kindly advise me?

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 'NULL ,

  `labpdfserial` VARCHAR NULL ,

  `isDoctor` TINYINT(1) NULL ,

  PRIMARY ' at line 48.

SQL Error: 1064

you have to declare a size for VARCHAR or CHAR datatypes.

oh… thanks for the tip. Was using mysql workbench to convert mssql to mysql.