In Oracle, the VARCHAR2(n) data type stores variable-length character strings up to n bytes (default) or characters with the maximum of 4000 or 32,767 bytes if MAX_STRING_SIZE initialization parameter is set to EXTENDED (not set by default).
In MySQL, you can use VARCHAR(n) that can store up to 65,535 characters. But effective maximum length is subject to the maximum row size limit of 65,535 bytes (shared among all columns) and the character set used.
Oracle:
CREATE TABLE specs ( note VARCHAR2(30), name VARCHAR2(100 CHAR), item VARCHAR2(50 BYTE) );
MySQL:
CREATE TABLE specs ( note VARCHAR(30), name VARCHAR(100), item VARCHAR(50) );
Conversion summary:
For more information, see Oracle to MySQL Migration.