Click7

When I ran:
CREATE TABLE wp_wcs2_classroom (
id INT(11) NOT NULL AUTO_INCREMENT,
classroom_name VARCHAR(256) NOT NULL DEFAULT ”,
classroom_description TEXT,
time_created VARCHAR(50) NOT NULL DEFAULT ”,
user_created BIGINT(20) NOT NULL,
time_modified VARCHAR(50) NOT NULL DEFAULT ”,
user_modified BIGINT(20) NOT NULL,
PRIMARY KEY (id),
UNIQUE KEY classroom_name (classroom_name)
);

Got: “Error Code : 1071
Specified key was too long; max key length is 767 bytes”