数据库db2写一个自定义函数实现数字转大写中文字符

你好，这是一个技术问题，我可以回答。以下是一个示例代码，可以将数字转换为大写中文字符：

CREATE FUNCTION num2chinese (num INT)
RETURNS VARCHAR(255)
DETERMINISTIC
BEGIN
DECLARE result VARCHAR(255);
DECLARE units VARCHAR(10) DEFAULT '个十百千万亿';
DECLARE nums VARCHAR(10) DEFAULT '零一二三四五六七八九';
DECLARE i INT DEFAULT ;
DECLARE len INT DEFAULT ;
DECLARE digit INT DEFAULT ;
DECLARE ch VARCHAR(10) DEFAULT '';

IF num = THEN
RETURN '零';
END IF;

SET result = '';

WHILE num > DO
SET digit = num % 10;
SET ch = SUBSTR(nums, digit+1, 1);
SET result = CONCAT(ch, SUBSTR(units, i+1, 1), result);
SET num = FLOOR(num / 10);
SET i = i + 1;
END WHILE;

SET len = LENGTH(result);

IF SUBSTR(result, len-1, 2) = '零十' THEN
SET result = CONCAT(SUBSTR(result, 1, len-2), '十');
END IF;

IF SUBSTR(result, len-1, 2) = '零百' THEN
SET result = CONCAT(SUBSTR(result, 1, len-2), '百');
END IF;

IF SUBSTR(result, len-1, 2) = '零千' THEN
SET result = CONCAT(SUBSTR(result, 1, len-2), '千');
END IF;

IF SUBSTR(result, len-1, 2) = '零万' THEN
SET result = CONCAT(SUBSTR(result, 1, len-2), '万');
END IF;

IF SUBSTR(result, len-1, 2) = '零亿' THEN
SET result = CONCAT(SUBSTR(result, 1, len-2), '亿');
END IF;

RETURN result;
END;

使用方法：

SELECT num2chinese(12345); -- 返回 "一万二千三百四十五"