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gs79
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query contd

In continuation with the below query:

https://www.experts-exchange.com/questions/28335810/query-to-parse-string.html


Sdstuber..Is there a way to get result it as one value rather than multiple records

I just want the result as a value not the records, the above example gives me 3 records instead of record with:
TGT.COL_B = SRC.COLB
TGT.COL_C = SRC.COL_C
TGT.COL_D = SRC.COL_D

Thanks
Oracle Database

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Sean Stuber

8/22/2022 - Mon
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Sean Stuber

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Sean Stuber

I aggregated them above with a space between each.
If you want them in a single string but each on their own line

then change the ' ' in LISTAGG to chr(10)


LISTAGG('TGT.' || str || ' = ' || 'SRC.' || str, chr(10))

on windows you might want to use

LISTAGG('TGT.' || str || ' = ' || 'SRC.' || str, chr(13) || chr(10))

example of chr(10) below


SELECT id, listagg('TGT.' || str || ' = ' || 'SRC.' || str,' ') within group( order by str)
  FROM (SELECT id,
               REGEXP_SUBSTR(
                   col_str,
                   '[^ ,]+',
                   1,
                   n
               )
                   str
          FROM yourtable,
               (    SELECT LEVEL n
                      FROM DUAL
                CONNECT BY LEVEL <= 10)
         WHERE REGEXP_SUBSTR(
                   col_str,
                   '[^ ,]+',
                   1,
                   n
               )
                   IS NOT NULL
        MINUS
        SELECT id,
               REGEXP_SUBSTR(
                   key,
                   '[^ ,]+',
                   1,
                   n
               )
          FROM yourtable,
               (    SELECT LEVEL n
                      FROM DUAL
                CONNECT BY LEVEL <= 10)
         WHERE REGEXP_SUBSTR(
                   key,
                   '[^ ,]+',
                   1,
                   n
               )
                   IS NOT NULL)
group by id 

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gs79

ASKER
I am also trying to generate the onclause for the merge query which is basically second part of the minus query. I am getting the results as follows:

TGT.COL_A = SRC.COL_A
TGT.COL_B = SRC.COL_B
TGT. = SRC.
TGT. = SRC.

here is the query I am using:
SELECT  listagg('TGT.' || str || ' = ' || 'SRC.' || str,chr(13)) within group( order by str)
from(
SELECT REGEXP_SUBSTR(key, '[^ ,]+',1,n) str
          FROM drop_test_tab,
               (    SELECT LEVEL n
                      FROM DUAL
                CONNECT BY LEVEL <= 10)
         WHERE REGEXP_SUBSTR(col_str, '[^ ,]+',1,n)  IS NOT NULL
)  

I am getting 4 rows with last two rows as blank from the inner query. I think 'IS NOT NULL' is intended to filter out the blank rows which is not happening

SELECT REGEXP_SUBSTR(key, '[^ ,]+',1,n) str
          FROM drop_test_tab,
               (    SELECT LEVEL n
                      FROM DUAL
                CONNECT BY LEVEL <= 10)
         WHERE REGEXP_SUBSTR(col_str, '[^ ,]+',1,n)  IS NOT NULL

The inner query gives the following result:
COL_A
COL_B
NULL
NULL

Please let me know how to resolve this..

Thanks
Sean Stuber

you have 2 different first parameters in the REGEXP_SUBSTR


key vs col_str


key should be in both parts of one half of the MINUS
and col_str should be in both parts of the other half


don't put both in both
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James Murphy
gs79

ASKER
Thanks..

It worked..

Is there a way to display as comma seperated. I can append a comma but it displays on the last line which is not needed:

TGT.COL_B = SRC.COL_B ,
TGT.COL_C = SRC.COL_C ,
TGT.COL_D = SRC.COL_D

Thanks
gs79

ASKER
further massaging the listagg output with substr /length function i was able to remove the comma in the end..

Thanks
Sean Stuber

just add the comma to the aggregate function's delimiter parameter  (the 2nd parameter)

so, if you're using chr(13) as your delimiter
then change...

  listagg('TGT.' || str || ' = ' || 'SRC.' || str, chr(13))

to

  listagg('TGT.' || str || ' = ' || 'SRC.' || str, ',' || chr(13))



no need to do any substr/length parsing, let the aggregate do it for you
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Sean Stuber

Do you need anything else?