error procedure mysql db - mysql

Question

I've created a procedure in my DB of a veterinary clinic that shows what is: the first date, the first time available with a veterinarian authorized to perform the service requested (there mustn't be other appointments booked at the same time). However when I call this procedure the cursor stops because the value of eof is 1, but it didn't really see all the records: the cursor leaves the loop before the end of rows! I can not understand why.
here is the code:
DELIMITER //
DROP PROCEDURE IF EXISTS first_booking_available //
CREATE PROCEDURE first_booking_available(IN Perf VARCHAR(30), IN DateP DATE)
BEGIN
DECLARE IdV, eof INTEGER;
DECLARE Dat DATE;
DECLARE i, TimeB, End TIME;
DECLARE vet CURSOR FOR E.Id_vet, W.Date, S.Start_time, S.End_time
FROM Enabled E, Work W, WorkShift S
WHERE E.Code_performance = Perf AND W.Id_vet = E.Id_vet AND S.Code = W.Code_workshift AND W.Date >= DateP ORDER BY W.Date, S.Start_time;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET eof = 1;
SELECT Duration INTO #Duration FROM Perfomance WHERE Code = Perf;
SET #Start_time = NULL;
OPEN vet;
read_loop: LOOP
FETCH vet INTO IdV, Dat, TimeB, End;
IF (eof = 1 OR #Start_time IS NOT NULL) THEN
LEAVE read_loop;
END IF;
SET i = TimeB;
WHILE i < End AND #Start_time IS NULL DO
SET #P = NULL;
SET #F = NULL;
SELECT ADDTIME(ADDTIME(B.Start_time, P.Duration), '00:01:00') INTO #P
FROM Booking B, Performance P
WHERE P.Code = B.Code_performance AND B.Date = Dat AND B.Id_vet = IdV AND B.Start_time = i;
SELECT ADDTIME(ADDTIME(B.Start_time, P.Duration), '00:01:00') INTO #F
FROM Booking B, Performance P
WHERE P.Code = B.Code_performance AND B.Date = Dat AND B.Id_vet = IdV AND B.Start_time BETWEEN i AND ADDTIME(i, #Duration) ORDER BY ADDTIME(B.Start_time, P.Duration) DESC LIMIT 1;
IF #P IS NOT NULL THEN
SET i = #P;
END IF;
IF #F IS NOT NULL THEN
SET i = #F;
END IF;
IF ADDTIME(i, #duration) > End THEN
SET i = End;
END IF;
IF ((#P IS NULL) AND (#F IS NULL) AND (i != End)) THEN
SET #Start_Time = i;
END IF;
END WHILE;
IF #Start_Time IS NOT NULL THEN
SET #Id_vet = IdV;
SET #Date = Dat;
END IF;
END LOOP;
CLOSE vet;
IF #Start_Time IS NULL THEN
SIGNAL sqlstate '99994'
SET MESSAGE_TEXT = 'there is no availability !';
END IF;
END //
DELIMITER ;

Answer 1

DECLARE CONTINUE HANDLER FOR NOT FOUND SET eof = 1;
is mean your query has no result. It is not apply just cursor, another select query too.
SELECT ADDTIME(ADDTIME(B.Start_time, P.Duration), '00:01:00') INTO #P
FROM Booking B, Performance P
WHERE P.Code = B.Code_performance AND B.Date = Dat AND B.Id_vet = IdV AND B.Start_time = i;
SELECT ADDTIME(ADDTIME(B.Start_time, P.Duration), '00:01:00') INTO #F
FROM Booking B, Performance P
WHERE P.Code = B.Code_performance AND B.Date = Dat AND B.Id_vet = IdV AND B.Start_time BETWEEN i AND ADDTIME(i, #Duration) ORDER BY ADDTIME(B.Start_time, P.Duration) DESC LIMIT 1;
this query has no result. HANDLER catch them. and leave cursor.