mysql. Stored Procedure Error 1328 - mysql

Question

This is really baffling me. I am converting a simple procedure from informix into mysql. What it basically does is tell me what the next event is from an event table and a calendar table. In informix the procedure is simple.
FOREACH
SELECT date,weekno,event
INTO l_date,l_week,l_event
FROM event,calendar
WHERE dayno = dayno
AND date = l_today
AND start >= l_now
UNION
SELECT date,weekno,event
FROM event,calendar
WHERE dayno = dayno
AND date > l_today
UNION
SELECT TODAY,9999,9999
FROM event,calendar
WHERE dayno = dayno
AND event = (SELECT MAX(event) FROM event)
ORDER BY 3
if l_event = 9999 then <error> end if;
EXIT FOREACH
END FOREACH
So basically the query finds the next event and returns it. l_today and l_event are parameters that are passed. So on to the mysql version.
looper: BEGIN
DECLARE curs1 CURSOR FOR
SELECT CONCAT("SELECT date, weekno, event FROM event INNER JOIN calendar ON dayno = dayno",
" WHERE date = '", lv_today ,"' AND start >= '", lv_time ,"'",
" UNION SELECT date, weekno, event FROM event INNER JOIN calendar ON dayno = dayno WHERE date > '", lv_today ,"'",
" UNION SELECT DATE(NOW()) AS date, 9999 AS weekno, 9999 AS event FROM event INNER JOIN calendar ON dayno = dayno",
" WHERE (SELECT MAX(event) FROM event) ORDER BY event ");
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done := TRUE;
OPEN curs1;
loop1: LOOP
FETCH curs1 INTO ldate, lweek, levent;
SELECT ldate, lweek, levent;
LEAVE looper;
END LOOP loop1;
END;
I haven't checked that the rest of the methodology works because I get this error:
Incorrect number of FETCH variables.
Does this mean that I have declare a different variable for each of the query returns? I am new to mysql. If this is the case what would be the best way to solve this conundrum? I have also changed to column and table names.
Many thanks

Answer 1

looper: BEGIN
DECLARE curs1 CURSOR FOR
SELECT eve_date, dia_weekno, eve_event
FROM game_event
INNER JOIN stan_calendar ON eve_abs_dayno = dia_abs_dayno
WHERE eve_date = lv_today
AND eve_start >= lv_time
UNION
SELECT eve_date, dia_weekno, eve_event
FROM game_event
INNER JOIN stan_calendar ON eve_abs_dayno = dia_abs_dayno
WHERE eve_date > lv_today
UNION SELECT DATE(NOW()) AS eve_date, 9999 AS dia_weekno, 9999 AS eve_event
FROM game_event
INNER JOIN stan_calendar ON eve_abs_dayno = dia_abs_dayno
WHERE (SELECT MAX(eve_event) FROM game_event) ORDER BY eve_event;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done := TRUE;
OPEN curs1;
curs_loop: LOOP
FETCH curs1 INTO lv_date, lv_week, lv_event;
SELECT lv_date, lv_week, lv_event;
LEAVE looper;
CLOSE curs1;
END LOOP curs_loop;
Thank you for answering my question, I have put it back to how I thought it was... and it now works. Here is the loop in full.

Answer 2

https://dev.mysql.com/doc/refman/5.7/en/fetch.html The number of columns retrieved by the SELECT statement must match the number of output variables specified in the FETCH statement so yes but in fact you are only selecting 1 concatenated string - I think your first problem is with the select syntax which doesn't need the concat, the brackets or the quotes (unless you are trying to create a prepared statement for some reason - and even if you were I doubt if the code would be correct)
Simple Cursor
DROP PROCEDURE IF EXISTS EC;
DELIMITER $$
CREATE PROCEDURE `EC`(
IN `inemp_no` varchar(255)
)
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
LOOPER:begin
DECLARE done INT DEFAULT FALSE;
declare ename varchar(20);
declare esalary int default 0;
declare emp_cursor CURSOR FOR
SELECT last_name,salary FROM employees where emp_no= inemp_no ;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
open emp_cursor;
read_loop: loop
fetch emp_cursor into ename,esalary;
if done then leave read_loop; end if;
insert into debug_table (msg) values(concat('employee:',ename,' earns:',esalary));
end loop;
close emp_cursor;
end $$
DELIMITER ;
MariaDB [sandbox]> truncate table debug_table;
Query OK, 0 rows affected (0.22 sec)
MariaDB [sandbox]> call ec(2);
Query OK, 0 rows affected (0.03 sec)
MariaDB [sandbox]> select * from debug_table;
+----+--------------------------+------+
| id | msg | MSG2 |
+----+--------------------------+------+
| 1 | employee:BBB earns:39500 | NULL |
+----+--------------------------+------+
1 row in set (0.00 sec)