mysql 叠加字符串,使用CONCAT函数和set关键字负责叠加后的赋值

DELIMITER $$

CREATE
/*[DEFINER = { user | CURRENT_USER }]*/
PROCEDURE `th_db`.`sp_test_concat_string`()
/*LANGUAGE SQL
| [NOT] DETERMINISTIC
| { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
| SQL SECURITY { DEFINER | INVOKER }
| COMMENT 'string'*/
BEGIN
DECLARE a INT;
DECLARE b VARCHAR(5000);
SET a=1;
SET b='';
WHILE a<50 DO

SET b=CONCAT(b,',',a);
SET a=a+1;
END WHILE;

SELECT b;

END$$

DELIMITER ;