Re: [問題] 1-9位數不重複印出來 (MySQL or MariaDB)

[shadowjohn (轉角遇到愛)]

※ 引述《mikemagic88 (Mikemagic88)》之銘言：
: 使用者輸入1  印1-9
: 使用者輸入2  印1-98  (11, 22, 33等重複的不印)
: 使用者輸入3  印1-987 (121, 988, 667等有重複的不印)

DROP FUNCTION IF EXISTS is_having_same_char;
CREATE FUNCTION is_having_same_char(num INT(10))
  RETURNS INT READS SQL DATA
BEGIN
  DECLARE isfound INT;
        DECLARE STEP INT;
        DECLARE WORD_LENGTH INT;
        DECLARE WORD TEXT;
        DECLARE THECHAR VARCHAR(1);
        SET isfound = 0;
        SET STEP=0;
        SET WORD_LENGTH=LENGTH(num);
        SET WORD='';
        SET THECHAR='';
        count_loop: LOOP
                SET STEP=STEP+1;
                SET THECHAR = SUBSTRING(num,STEP,1);
                IF INSTR(WORD,THECHAR) != 0 THEN
                        #SET isfound = 1;
                        #LEAVE count_loop;
                        RETURN 1;
                END IF;
                set WORD = concat(WORD,THECHAR);
                IF STEP >= WORD_LENGTH THEN
      LEAVE count_loop;
    END IF;
        END LOOP;
        RETURN isfound;
END;


DROP FUNCTION IF EXISTS mycode;
CREATE FUNCTION mycode(num INT(10))
  RETURNS LONGTEXT READS SQL DATA
BEGIN
        DECLARE step INT;
        DECLARE OUTPUT LONGTEXT;
        SET OUTPUT = '';
        SET step = 0;
  count_loop: LOOP
    SET step = step + 1;
                IF is_having_same_char(step) = 0 THEN
                        SET OUTPUT = CONCAT(OUTPUT,step,", ");
                END IF;
    IF step = POW(10,num)-1 THEN
      LEAVE count_loop;
    END IF;
  END LOOP;
  RETURN SUBSTRING(OUTPUT,1,LENGTH(OUTPUT)-2);
END;


# 使用方式
select mycode(3);


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