生成随机字符串(SQL函数)(http://www.jb51.net/article/61362.htm)

rand_str.sql

DROP FUNCTION `test`.`rand_str`;

SET GLOBAL log_bin_trust_function_creators=TRUE;

DELIMITER $$

CREATE
    /*[DEFINER = { user | CURRENT_USER }]*/
    FUNCTION `test`.`rand_str`(n INT UNSIGNED)
    RETURNS VARCHAR(2000)
    /*LANGUAGE SQL
    | [NOT] DETERMINISTIC
    | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
    | SQL SECURITY { DEFINER | INVOKER }
    | COMMENT 'string'*/
    BEGIN

	DECLARE char_str VARCHAR(100) DEFAULT 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
	DECLARE return_str VARCHAR(2000) DEFAULT '';
	DECLARE i INT DEFAULT 0;
	WHILE i < n DO 
		SET return_str = CONCAT(return_str,SUBSTRING(char_str , FLOOR(1 + RAND()*62 ),1));
		SET i = i +1;
	END WHILE;
	RETURN return_str;

    END$$

DELIMITER ;