EXCEPT command - Find sailors who’ve reserved all boats

I am reading a textbook and I do not understand this query: Find sailors who’ve reserved all boats.

• We have 3 tables:
  1. Sailors: sid, sname, rating, age (primary: sid)
  2. Boats: bid (primary: bid)
  3. Reserves: sid, bid, day (primary, sid, bid, day) (sid is foreign key to sailors, bid is foreign key to boats)

For the query, Find sailors who’ve reserved all boats, the answer given is:

SELECT  S.sname
FROM  Sailors S
WHERE  NOT EXISTS 
          ((SELECT  B.bid
             FROM  Boats B)
            EXCEPT
             (SELECT  R.bid
              FROM  Reserves R
              WHERE  R.sid=S.sid))

My questions are:

1. Is there something wrong with the above query? When I put it into MySQL Workbench, it shows I have syntax error with the EXCEPT

2. Beside the solution given by the book above, is there any other way to do the query: Find sailors who’ve reserved all boats

Thank you,

You can do this using COUNT and CONCAT. This query selects the sailors that are paired (in the Reserves table) with each boat in the boat table:

SELECT Sailors.name
FROM Sailors INNER JOIN
(SELECT Reserves.sid
 FROM Reserves
 GROUP BY Reserves.sid
 HAVING COUNT(DISTINCT CONCAT(Reserves.sid, Reserves.bid)) =
 (SELECT COUNT(DISTINCT Boats.bid)
  FROM Boats)) sub
ON Sailors.sid = sub.sid

Tested here: http://sqlfiddle.com/#!9/82005/2