extract values after comma's using regexp

Question

Am using Oracle 19c database

Below is my string value

variable B1 varchar2(60)
exec :B1:='(199,''TEST121''),(156,''TEST''),(1561,''TEST99'')';

I want the output as

|    ID    |     NAME       |
| -------- | -------------- |
|       199|   TEST121      |
|       156|   TEST         |
|      1561|   TEST99       |

select  regexp_substr(regexp_substr(:b1,'[^A-Z+0-9][0-9]+', 1,level),'[0-9]+') as id , regexp_substr(:b1,'[A-Z]+[0-9]', 1,level) as name from dual connect by regexp_substr(:b1,'[0-9]', 1,level) is not null;

This query is only giving output for string values ending with digits.

score 1 · Accepted Answer · answered May 25 '21 at 06:32

Here's one option:

SQL> WITH
  2     test (col)
  3     AS
  4        (SELECT '(199,''TEST121''),(156,''TEST''),(1561,''TEST99'')' FROM DUAL)
  5  SELECT SUBSTR (str, 1, INSTR (str, ',') - 1) id,
  6         SUBSTR (str, INSTR (str, ',') + 1) name
  7    FROM (    SELECT REGEXP_SUBSTR (
  8                        REPLACE (
  9                           REPLACE (
 10                              REPLACE (REPLACE (col, '),(', '#'), CHR (39), ''),
 11                              '(',
 12                              ''),
 13                           ')',
 14                           ''),
 15                        '[^#]+',
 16                        1,
 17                        LEVEL) str
 18                FROM test
 19          CONNECT BY LEVEL <= REGEXP_COUNT (REPLACE (col, '),(', '#'), '#') + 1);

ID                               NAME
-------------------------------- --------------------------------
199                              TEST121
156                              TEST
1561                             TEST99

SQL>

What does it do?

lines #1 - 4 - sample data
lines #8 - 14 - replace ),( with # (to get a simpler separator); remove leading and trailing brackets
lines #7 - 19 - split sample string into rows
lines #5, 6 - extract ID and NAME out of each row

Sure, there are quite a few other options. Pick the one that suits you best. — Littlefoot, May 25 '21 at 07:55
Thank you very much. It works perfect.. Can you explain the 19th line using regexp_count — pavankumar2028, May 25 '21 at 08:23
It counts number of separators in the input string and adds 1 to it (i.e. if there are two separators (#, right?), result is 3). It means that there are 3 "substrings", each of them representing a "row". — Littlefoot, May 25 '21 at 08:33

score 0 · Answer 2 · answered May 25 '21 at 19:10

Detailed explanation of the option given by @Littlefoot

Below is the test case for which multivalued string is converted in to columns and rows.

    set lines 999 pages 999
    col ID for a20
    col NAME for a20
    
    variable B1 varchar2(60)
    exec :B1:='(99,''TABLE1''),(56,''INDEX1''),(199,''TABLE''),(156,''INDEX'')';
    variable B1 varchar2(100)
    exec :B1:='(''TABL234E1~'',99),(''I1NDEX1~'',5ABC6),(''TAB1LE'',4ABC0),(''IND11EX'',6ACDE0)';
    
    WITH
       test (col)
       AS
          (SELECT :b1 FROM DUAL)
    SELECT SUBSTR (str, 1, INSTR (str, ',') - 1) id,
           SUBSTR (str, INSTR (str, ',') + 1) name
      FROM (    SELECT REGEXP_SUBSTR (
                          REPLACE (
                             REPLACE (
                                REPLACE (REPLACE (col, '),(', '#'), CHR (39), ''),
                                '(',
                                ''),
                             ')',
                             ''),
                          '[^#]+',
                          1,
                          LEVEL) str
                  FROM test
            CONNECT BY LEVEL <= REGEXP_COUNT (REPLACE (col, '),(', '#'), '#') + 1);

explanation:

    variable B1 varchar2(60)
    
    exec :B1:='(99,''TABLE1''),(56,''INDEX1''),(199,''TABLE''),(156,''INDEX'')';

STEP1

    WITH
      test (col)
      AS
         (SELECT :b1 FROM DUAL)
      select col from test;

This step helps in getting base string in oracle row format.

Result:

     (99,'TABLE1'),(56,'INDEX1'),(199,'TABLE'),(156,'INDEX')

STEP2

    WITH
      test (col)
      AS
         (SELECT :b1 FROM DUAL)
      select REPLACE(col, '),(','#') from test;

This step helps in replacing '),(' with '#' (to get a simpler separator for multivalued string).

Result :

    (99,'TABLE1'#56,'INDEX1'#199,'TABLE'#156,'INDEX')

STEP3

    WITH
      test (col)
      AS
         (SELECT :b1 FROM DUAL)
      select REPLACE(REPLACE(col, '),(','#'),CHR(39),'') from test;

This step helps in replacing single quotes from the preceding step.

Result:

    (TABL234E1~,99#I1NDEX1~,5ABC6#TAB1LE,4ABC0#IND11EX,6ACDE0)

STEP4

    WITH
      test (col)
      AS
         (SELECT :b1 FROM DUAL)
      select REPLACE(REPLACE(REPLACE(col, '),(','#'),CHR(39),''),'(','') from test;

This step helps in replacing '(' with '' (to remove the leading bracket from preceding step).

Result:

    99,TABLE1#56,INDEX1#199,TABLE#156,INDEX)

STEP5

    WITH
      test (col)
      AS
         (SELECT :b1 FROM DUAL)
      select REPLACE(REPLACE(REPLACE(REPLACE(col, '),(','#'),CHR(39),''),'(',''),')','') from test;

This step helps in replacing ')' with '' (to remove the trailing bracket from preceding step).

Result:

   99,TABLE1#56,INDEX1#199,TABLE#156,INDEX

STEP6

    WITH
       test (col)
       AS
          (SELECT :b1 FROM DUAL)
    SELECT *
      FROM (    SELECT REGEXP_SUBSTR (
                          REPLACE (
                             REPLACE (
                                REPLACE (REPLACE (col, '),(', '#'), CHR (39), ''),
                                '(',
                                ''),
                             ')',
                             ''),
                          '[^#]+',
                          1,
                          LEVEL) str
                  FROM test
            CONNECT BY LEVEL <= REGEXP_COUNT (REPLACE (col, '),(', '#'), '#') + 1);

This step have 2 components :

    a. REGEXP_SUBSTR(<value from previous step>,'[^#]+',1,LEVEL)
    '[^#]+' ==> searches and gets every character other than '#' 
    1==> starting position of the searches
    LEVEL==> LEVEL can be used in conjunction with CONNECT BY LEVEL clause. All the chunks of the source string can be displayed by using the LEVEL keyword as the match occurrence. 

    b. CONNECT BY LEVEL <= REGEXP_COUNT (REPLACE (col, '),(', '#'), '#') + 1
    REPLACE (col, '),(', '#') ==> This helps in replacing '),(' with '#' (to get a simpler separator for multivalued string).
    REGEXP_COUNT(<output from previous step>,'#')+1==> Count the number of '#' +1 in the source string. 
    Here, the CONNECT BY LEVEL clause generates the rows equal to the number of '#' +1 in the source string.

Result:

    99,TABLE1
    56,INDEX1
    199,TABLE
    156,INDEX

STEP7

    WITH
       test (col)
       AS
          (SELECT :b1 FROM DUAL)
    SELECT SUBSTR (str, 1, INSTR (str, ',') - 1) id,
           SUBSTR (str, INSTR (str, ',') + 1) name
      FROM (    SELECT REGEXP_SUBSTR (
                          REPLACE (
                             REPLACE (
                                REPLACE (REPLACE (col, '),(', '#'), CHR (39), ''),
                                '(',
                                ''),
                             ')',
                             ''),
                          '[^#]+',
                          1,
                          LEVEL) str
                  FROM test
            CONNECT BY LEVEL <= REGEXP_COUNT (REPLACE (col, '),(', '#'), '#') + 1);

This step have 2 components : a.SUBSTR (str, 1, INSTR (str, ',') - 1)==> str is tken from preceding output and starting from 1st postion it greps the characters from ',' to -1 position. b.SUBSTR (str, INSTR (str, ',') + 1) name==> str is tken from preceding output and starting from ',' it greps the characters from ',' to +1 position.

Result:

    ID                   NAME
    -------------------- --------------------
    99                   TABLE1
    56                   INDEX1
    199                  TABLE
    156                  INDEX

extract values after comma's using regexp

2 Answers2

explanation:

STEP1

STEP2

STEP3

STEP4

STEP5

STEP6

STEP7