SQL Split String to letters each one in row

Question

I have case to get String from table , Split it to letters , each letter represent "active/inactive" "0/1" , then return description from other table for just all active letter IN ONE CELL .. NOTE: Letters order as it is in other table ..

this is my case :

CREATE TABLE Strings_tab
(
   Str_id     NUMBER,
   Str_text   VARCHAR2 (40)
);

CREATE TABLE Reprsnt_Tab
(
   rep_id     NUMBER,
   rep_text   VARCHAR2 (40)
);

INSERT INTO Strings_tab VALUES (1, '1111111111000000000011111111110000000000');
INSERT INTO Strings_tab VALUES (2, '0000011111000001111100000111110000011111');

INSERT INTO Reprsnt_Tab VALUES (1, 'rep1');
INSERT INTO Reprsnt_Tab VALUES (2, 'rep2');
INSERT INTO Reprsnt_Tab VALUES (3, 'rep3');   
INSERT INTO Reprsnt_Tab VALUES (4, 'rep4');
INSERT INTO Reprsnt_Tab VALUES (5, 'rep5');
INSERT INTO Reprsnt_Tab VALUES (6, 'rep6');
INSERT INTO Reprsnt_Tab VALUES (7, 'rep7');
INSERT INTO Reprsnt_Tab VALUES (8, 'rep8');
INSERT INTO Reprsnt_Tab VALUES (9, 'rep9');
INSERT INTO Reprsnt_Tab VALUES (10, 'rep10');
INSERT INTO Reprsnt_Tab VALUES (11, 'rep11');
INSERT INTO Reprsnt_Tab VALUES (12, 'rep12');
INSERT INTO Reprsnt_Tab VALUES (13, 'rep13');
INSERT INTO Reprsnt_Tab VALUES (14, 'rep14');
INSERT INTO Reprsnt_Tab VALUES (15, 'rep15');
INSERT INTO Reprsnt_Tab VALUES (16, 'rep16');
INSERT INTO Reprsnt_Tab VALUES (17, 'rep17');
INSERT INTO Reprsnt_Tab VALUES (18, 'rep18');
INSERT INTO Reprsnt_Tab VALUES (19, 'rep19');
INSERT INTO Reprsnt_Tab VALUES (20, 'rep20');
INSERT INTO Reprsnt_Tab VALUES (21, 'rep21');
INSERT INTO Reprsnt_Tab VALUES (22, 'rep22');
INSERT INTO Reprsnt_Tab VALUES (23, 'rep23'); 
INSERT INTO Reprsnt_Tab VALUES (24, 'rep24');
INSERT INTO Reprsnt_Tab VALUES (25, 'rep25');
INSERT INTO Reprsnt_Tab VALUES (26, 'rep26');
INSERT INTO Reprsnt_Tab VALUES (27, 'rep27');
INSERT INTO Reprsnt_Tab VALUES (28, 'rep28');
INSERT INTO Reprsnt_Tab VALUES (29, 'rep29');
INSERT INTO Reprsnt_Tab VALUES (30, 'rep30');
INSERT INTO Reprsnt_Tab VALUES (31, 'rep31');
INSERT INTO Reprsnt_Tab VALUES (32, 'rep32');
INSERT INTO Reprsnt_Tab VALUES (33, 'rep33');
INSERT INTO Reprsnt_Tab VALUES (34, 'rep34');
INSERT INTO Reprsnt_Tab VALUES (35, 'rep35');
INSERT INTO Reprsnt_Tab VALUES (36, 'rep36');
INSERT INTO Reprsnt_Tab VALUES (37, 'rep37');
INSERT INTO Reprsnt_Tab VALUES (38, 'rep38');
INSERT INTO Reprsnt_Tab VALUES (39, 'rep39');  
INSERT INTO Reprsnt_Tab VALUES (40, 'rep40');

COMMIT;

this is my query :

SELECT STR_TEXT,
       RTRIM (
          XMLAGG (XMLELEMENT (E, DATA.REP_TEXT || ',' || CHR (10))).EXTRACT (
             '//text()'),
          ',')
          REPS
  FROM (  SELECT LETTER,
                 STR_ID,
                 LVL,
                 STR_TEXT,
                 REP_TEXT
            FROM (    SELECT DISTINCT SUBSTR (A.STR_TEXT, LEVEL, 1) LETTER,
                                      A.STR_ID,
                                      LEVEL LVL,
                                      A.STR_TEXT
                        FROM STRINGS_TAB A
                  CONNECT BY LEVEL <= LENGTH (A.STR_TEXT) ---- HERE IS MY PROBLEM
                                        ) TXT,
                 (  SELECT ROWNUM RN, REPRSNT_TAB.*
                      FROM REPRSNT_TAB
                  ORDER BY REP_ID) B
           WHERE B.RN = TXT.LVL AND LETTER = 1
        ORDER BY STR_ID, STR_TEXT, LVL) DATA
        GROUP BY STR_TEXT

This query get correct data If i put like 10 in place of "LENGTH (A.STR_TEXT)" to get first 10 letters of each string. BUT .. If "LENGTH (A.STR_TEXT)" was so big , in my case 40 , the query will hang so, please , advice me .. in this case ???

RESULT from my Query , IF I put "LEVEL <= 10" :

       STR_TEXT                         REP
------------------------------- ------------------------------
000001111100000111110000011111  rep6,rep10,rep9,rep8,rep7
111111111100000000001111111111  rep1,rep10,rep9,rep8,rep7,rep6,rep5,rep4,rep3,rep2

Answer 1

select Str_id
      ,Str_text
      ,xmlquery('let $abc :=  for $i in 1 to string-length($str) 
                              where substring($str, $i, 1) = "1" 
                                   return $data/rows/row[$i]/text() 
                    return  string-join( $abc, ",")' 
        passing   Str_text as "str"
              , (select xmlelement("rows",xmlagg(xmlelement( "row",rep_text)  order by rep_id)) from Reprsnt_Tab) as "data" 
       returning content
     ) from Strings_tab

The table Reprsnt_Tab is aggregate to one xmlelemtnt. To access selected row you have to just do $doc/rows/row[$selected_row_nr]/text()

Answer 2

This is My Answer :

  SELECT str_text,
         LISTAGG (DATA.REP_TEXT, ',' || CHR (10))
            WITHIN GROUP (ORDER BY DATA.rn_rep)
            reps
    FROM (SELECT *
            FROM (  SELECT str_text, SUBSTR (str_text, rn, 1) OneDigit, rn
                      FROM (SELECT str_text FROM STRINGS_TAB) txt,
                           (    SELECT ROWNUM rn
                                  FROM DUAL
                            CONNECT BY LEVEL <=
                                          (SELECT MAX (LENGTH (str_text))
                                             FROM STRINGS_TAB)) rep
                     WHERE REP.RN <= LENGTH(str_text)
                  ORDER BY Str_text, rn) xx,
                 (  SELECT ROWNUM rn_rep, rep_text
                      FROM REPRSNT_TAB
                  ORDER BY rn_rep) desc_rep
           WHERE desc_rep.rn_rep = xx.rn AND OneDigit = 1) data
GROUP BY str_text

Answer 3

My approach takes the CONNECT BY to an auxiliary table (using CONNECT BY LEVEL in a table with more than 1 row is not a good idea IMHO. Look here) :

with aux as (select level as lvl
               from dual
              connect by level <= (select max(length(str_text)) from  strings_tab))
SELECT STR_TEXT,
       RTRIM (
          XMLAGG (XMLELEMENT (E, DATA.REP_TEXT || ',' || CHR (10))).EXTRACT (
             '//text()'),
          ',')
          REPS
  FROM (  SELECT LETTER,
                 STR_ID,
                 LVL,
                 STR_TEXT,
                 REP_TEXT
            FROM (    SELECT DISTINCT SUBSTR (A.STR_TEXT, LVL, 1) LETTER,
                                      A.STR_ID,
                                      LVL,
                                      A.STR_TEXT
                        FROM STRINGS_TAB A join aux x on x.lvl <=LENGTH (A.STR_TEXT)
                                        ) TXT,
                 (  SELECT ROWNUM RN, REPRSNT_TAB.*
                      FROM REPRSNT_TAB
                  ORDER BY REP_ID) B
           WHERE B.RN = TXT.LVL AND LETTER = 1
        ORDER BY STR_ID, STR_TEXT, LVL) DATA
        GROUP BY STR_TEXT;

OUTPUT (WITHOUT (CHAR(10))

STR_TEXT                                    REPS
0000011111000001111100000111110000011111    rep6,rep40,rep39,rep38,rep37,rep36,rep30,rep29,rep28,rep27,rep26,rep20,rep19,rep18,rep17,rep16,rep10,rep9,rep8,rep7
1111111111000000000011111111110000000000    rep1,rep30,rep29,rep28,rep27,rep26,rep25,rep24,rep23,rep22,rep21,rep10,rep9,rep8,rep7,rep6,rep5,rep4,rep3,rep2