Editable view - error = current selection does not contain a unique column

[Danny Bowen]

Trying to set up my first MySQL database and create an editable view combining 2 tables (cd, staff) on the ID of the second (staff). Both tables have PRIMARY keys that are set as PRIMARY, UNSIGNED, AUTO_INCREMENTED. I have tried including just the columns I want as well as every single column from both tables, but I continue to get the error message: "Current selection does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available."

When I run Explain SQL in phpMyAdmin, it shows
ID 1 1
select_type SIMPLE SIMPLE
table cd staff
type ALL eq_ref
possible_keys NULL PRIMARY
key NULL PRIMARY
key_len NULL 4
ref NULL [database name].cd.cd_staff
row 1 1
extra Using where

Here is the select statement from which the view was created:
SELECT
staff.staff_id,
staff.title,
staff.first_name,
staff.last_name,
staff.email,
staff.phone,
staff.ext,
staff.rooms,
cd.cd_id,
cd.cd_staff,
cd.cd_train,
cd.cd_avail,
cd.cd_notes
FROM cd
JOIN staff
ON cd.cd_staff = staff.staff_id

Any help would be appreciated.