MySql determines the specific functions of Chinese characters, dates, and numbers

DROP FUNCTION IF EXISTS fc_is_hanzi;

CREATE FUNCTION fc_is_hanzi(
p_str VARCHAR(1024)
)
  RETURNS int(11)
  NOT DETERMINISTIC
  SQL SECURITY DEFINER
  COMMENT 'Check whether the string is Chinese character'
BEGIN
/* Check whether the string is a Chinese character Return value: 1-Chinese character 0-Non-Chinese character*/

  DECLARE _ret, i, other_cnt, l_acode INT DEFAULT 0;
  SET _ret = 0;
  SET i = 1;
  SET other_cnt = 0;
  SET l_acode = 0;
  WHILE i <= CHAR_LENGTH(p_str) DO
    SET l_acode = ASCII(SUBSTRING(p_str, i, 1));
    IF l_acode<124 or l_acode>254 THEN
      SET other_cnt = other_cnt + 1;
    END IF;
    SET i = i + 1;
  END WHILE;
  IF other_cnt = 0 THEN
    SET _ret = 1;
  ELSE
    SET _ret = 0;
  END IF;
  RETURN _ret;
END;

DROP FUNCTION IF EXISTS fc_ck_date;

CREATE FUNCTION fc_ck_date(
p_cont CHAR(32) 
)
  RETURNS tinyint(4)
  NOT DETERMINISTIC
  SQL SECURITY DEFINER
  COMMENT 'Determine whether the date format is correct'
BEGIN
/*Determine whether the date format is correct (return value: 1-correct 0-error)*/
/*The input value format is: yyyyMMdd or yyyy-MM-dd*/

IF(SELECT DATE_FORMAT(p_cont,'%Y%m%d')) IS NULL THEN
  RETURN 0;
ELSE
  RETURN 1;
END IF;

END;

DROP FUNCTION IF EXISTS fc_is_num;

CREATE FUNCTION fc_is_num(
p_string VARCHAR(32) 
)
  RETURNS int(4)
  NOT DETERMINISTIC
  SQL SECURITY DEFINER
  COMMENT 'Check if the string is a pure number'
BEGIN
/* Check if the string is a pure number*/
/*Return value: 1-is a pure number 0-is a non-non-is a pure number*/

   DECLARE iResult INT DEFAULT 0;
   SELECT p_string REGEXP '^[0-9]*$' INTO iResult;
   IF iResult = 1 THEN
    RETURN 1;
   ELSE
     RETURN 0;
   END IF;
END;