J'ai utilisé cursor_loop: boucle dans la procédure stockée sql son ne récupérant pas toutes les 15 lignes il récupère une seule ligne

Question

Ici c'est mon code pour chercher 15 lignes dans le curseur..Mais son aller chercher une rangée ne va pas chercher 15 lignes aucune erreur dans ce code .Tout aide serait appréciée .REMERCIE à l'avance

delimiter $$ 

drop procedure if exists retrieve_relstr_roc_price; 

create procedure retrieve_relstr_roc_price(
    in p_begin_date  datetime 
) 
begin 

    declare no_more_rows  boolean; 
    declare l_symbol   varchar(10); 
    declare l_commit_rows int default 60; 
declare l_row_num  int default 0; 

declare roc_value_cursor cursor for 
     select * from(select distinct(symbol) as symbol from 
eqt_price_ta_relstr where category_name in ((select * from (select 
sn.category_name from eqt_price_ta_relstr ept 
inner join sectornames sn on sn.symbol = ept.symbol where ept.category_name 
= "SPsector" and ept.close_date >= p_begin_date group by sn.category_name order by ept.rank5 limit 0,1) t4 )) and close_date >= p_begin_date group by symbol order by rank5 limit 15) as t1;  
    declare continue handler for not found set no_more_rows = true; 


    open roc_value_cursor; 
    cursor_loop: loop 
    fetch roc_value_cursor 
    into l_symbol; 
    if no_more_rows 
    then 
    close roc_value_cursor; 
    leave cursor_loop; 
    end if; 

/*next part code used the cursor value*/ 

Answer 1

Je ne peux pas reproduire le problème:

mysql> DROP TABLE IF EXISTS `t1`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> CREATE TABLE IF NOT EXISTS `t1` (
    -> `symbol` VARCHAR(10) 
    ->); 
Query OK, 0 rows affected (0.01 sec) 

mysql> INSERT INTO `t1` 
    -> VALUES ('symbol 1'), ('symbol 2'), 
    ->  ('symbol 3'), ('symbol 4'), 
    ->  ('symbol 5'), ('symbol 6'), 
    ->  ('symbol 7'), ('symbol 8'), 
    ->  ('symbol 9'), ('symbol 10'), 
    ->  ('symbol 11'), ('symbol 12'), 
    ->  ('symbol 13'), ('symbol 14'), 
    ->  ('symbol 15'); 
Query OK, 15 rows affected (0.00 sec) 
Records: 15 Duplicates: 0 Warnings: 0 

mysql> DROP PROCEDURE IF EXISTS `retrieve_relstr_roc_price`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> DELIMITER // 

mysql> CREATE PROCEDURE `retrieve_relstr_roc_price`() 
    -> BEGIN 
    -> DECLARE `no_more_rows` BOOL DEFAULT FALSE; 
    -> DECLARE `l_symbol` VARCHAR(10); 
    -> DECLARE `l_row_num` INT UNSIGNED DEFAULT 0; 
    -> DECLARE `roc_value_cursor` CURSOR FOR 
    -> SELECT * -- It's recommended to identify the columns: SELECT `symbol` ... 
    -> FROM (
    ->   SELECT `symbol` 
    ->   FROM `t1` 
    ->  ) `der`; 
    -> DECLARE CONTINUE HANDLER FOR NOT FOUND SET `no_more_rows` := TRUE; 
    -> OPEN `roc_value_cursor`; 
    -> `cursor_loop`: LOOP 
    ->  FETCH `roc_value_cursor` INTO `l_symbol`; 
    ->  IF `no_more_rows` THEN 
    ->  CLOSE `roc_value_cursor`; 
    ->  LEAVE `cursor_loop`; 
    ->  END IF; 
    ->  SET `l_row_num` := `l_row_num` + 1; 
    -> END LOOP `cursor_loop`; 
    -> SELECT `l_row_num`; 
    -> END// 
Query OK, 0 rows affected (0.00 sec) 

mysql> DELIMITER ; 

mysql> CALL `retrieve_relstr_roc_price`; 
+-------------+ 
| `l_row_num` | 
+-------------+ 
|   15 | 
+-------------+ 
1 row in set (0.01 sec) 

Query OK, 0 rows affected (0.01 sec) 

Voir db-fiddle.