String Validation using SQL!

Use instring to find occurrence of spaces, substring to snip out, case statement for these for your cases.

your description of intended output does not match the output you have shown.

Is this a learning exercise or actual production requirement?

What if there are 5, 6, or 20 words?

Assuming your printed output is correct and your description is wrong then try something like this...

  SELECT ename_input,
         LISTAGG(SUBSTR(str, 1, CASE WHEN cnt = 1 THEN 4 WHEN cnt = 2 THEN 2 WHEN cnt > 2 AND rn = 1 THEN 2 ELSE 1 END))
             WITHIN GROUP (ORDER BY rn)
    FROM (SELECT ename_input,
                 str,
                 cnt,
                 ROW_NUMBER() OVER(PARTITION BY ename_input ORDER BY rn) rn
            FROM (SELECT ename_input,
                         COLUMN_VALUE str,
                         ROWNUM rn,
                         COUNT(*) OVER (PARTITION BY ename_input) cnt
                    FROM name, TABLE(str2tbl(REGEXP_REPLACE(ename_input, ' +', ' '), ' '))) x)
GROUP BY ename_input;


str2tbl is function you will need to create if you don't already ahve it
you can search for it on google or EE
there are lots of examples

I was thinking the CASE looked off.

4 words doesn't produce expected output:  kajja instead of kjja

Hi @sdstuber I have created the function "str2tab" and the o/p looks little differ  .

But here the requirement is if there are more than 4 word then it should pick only the 1st letter of each word.

SELECT name_input,
         LISTAGG(SUBSTR(str, 1, CASE WHEN cnt = 1 THEN 4 WHEN cnt = 2 THEN 2 WHEN cnt > 2 AND rn = 1 THEN 2 ELSE 1 END))
             WITHIN GROUP (ORDER BY rn)
    FROM (SELECT name_input,
                 str,
                 cnt,
                 ROW_NUMBER() OVER(PARTITION BY name_input ORDER BY rn) rn
            FROM (SELECT name_input,
                         COLUMN_VALUE str,
                         ROWNUM rn,
                         COUNT(*) OVER (PARTITION BY name_input) cnt
                    FROM string_tab, TABLE(str2tbl(REGEXP_REPLACE(name_input, ' +', ' '), ' '))) x)
GROUP BY name_input;

O/P
-----
       kali
     	kaja
       kajj
       kajja  -- Here it picked 1st 2 letter 

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Is this a learning exercise or actual production requirement?

Hi @slightwv this is required for production implementation.


Thanks

>>>>  kajja  -- Here it picked 1st 2 letter

maybe  it didn't, it just looks like it did.
what are the inputs for those outputs?

"kalia  jag  jagdish  acharya" > kajja,  2 letters from the first, 1st letter from each of the next 3 words.  Just because the 3rd word happens to have "ja" at the beginning doesn't mean the code picked 2 letters,  the 4th word begins with "a"

for more than 4 words, do you want the 1st letter of all words, including the first, or 2 from the first and 1 from every word thereafter?

If it's 2 from the 1st and 1 for everything thereafter, what I posted already does that.

If it's 1 from every word, then simply change
WHEN cnt > 2
to
WHEN cnt <=4

For more than 4 words, do you want the 1st letter of all words, including the first, or 2 from the first and 1 from every word thereafter?

If there are 4 or more than 4 words then it should pick only the 1st letter of the word and so on ...

"kalia jag jagdish acharya"                      --  kjja
"kalia jay jagdish acharya hello"             -- kjjah
"kalia jay jagdish acharya hello how"    -- kjjahh

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Thanks.

Perfect! Thanks , This is accurate as expected o/p.