SQL & PL/SQL

Announcement

For appeals, questions and feedback about Oracle Forums, please email oracle-forums-moderators_us@oracle.com. Technical questions should be asked in the appropriate category. Thank you!

Interested in getting your voice heard by members of the Developer Marketing team at Oracle? Check out this post for AppDev or this post for AI focus group information.

SQL work for single row and not multiple

LudyNov 17 2009 — edited Nov 18 2009

Hi,

I am trying to cut the text from row2 based on the format on row1 from table A,
It works fine for a single row inserted into A,
but when i added the second row it does not work as expected.

Can you let me know where we need to alter the sql statement.

CREATE TABLE A( A_ID VARCHAR2(50), A_TEXT VARCHAR2(200));
INSERT INTO A(A_ID,A_TEXT) VALUES('13233424','ABCDEFGHIJKLMNOPQRSTUV');
INSERT INTO A(A_ID,A_TEXT) VALUES('13233424','WXYZABCDEFGHIJKLMNOPQR');

WITH split_a_id AS
( SELECT a_text,
SUM(to_number(SUBSTR(a_id || '0',-level,1))) over (order by ROWNUM) AS cut_length
FROM a
CONNECT BY level<=LENGTH(a_id)
)
SELECT spl.cut_text
FROM
(SELECT SUBSTR(a_text,1,LENGTH(a_text) - cut_length) cut_text
FROM split_a_id
) spl

OUTPUT :
------------------------------------

CUT_TEXT
------------------------------
ABCDEFGHIJKLMNOPQRSTUV
ABCDEFGHIJKLMNOPQR
ABCDEFGHIJKLMNOP
ABCDEFGHIJKL
ABCDEFGHI
ABCDEF
ABCD
A
WXYZABCDEFGHIJKLMNOPQR
WXYZABCDEFGHIJKLMN
WXYZABCDEFGHIJKL
WXYZABCDEFGH
WXYZABCDE
WXYZAB
WXYZ
W

For Reference Initial Post at:
990152

This post has been answered by Frank Kulash on Nov 17 2009

Jump to Answer

Frank Kulash

Answer

Hi,

When you say "CONNECT BY LEVEL <= x" , make sure at least one of the following is true:
(1) the table in the query has only one row, or
(2) you know what you're doing.

In other situations, create a Counter Table that has all the numbers you'll ever need, and join to the Counter Table where you otherwise would do a CONNECT BY.
In the definition for the Counter Table, the CONNECT BY clause will resemble your original CONNECT BY clause, but instead of "CONNECT BY LEVEL <= x" it will be "CONNECT LEVEL <= *(SELECT MAX (x) ...)* ".
When you use the counter table, the join condition will be similar to your original CONNECT BY condition.

WITH	cntr	AS
(
	SELECT	LEVEL	AS n
	FROM	dual
	CONNECT BY	LEVEL <= ( SELECT MAX (LENGTH (a_id))
			      	   FROM	  a
				 )
)
,	split_a_id	AS
(
	SELECT	  a.a_text,
--		  a.a_id,	-- For debugging only
--		  c.n,	-- For debugging only
		  SUM (TO_NUMBER ( SUBSTR ( a.a_id || '0'
	    	       	 	 	  , -c.n
					  , 1
					  )
				  )
	    	      ) OVER ( PARTITION BY  a.a_text
		      	       ORDER BY      c.n
			     )	AS cut_length
	FROM      a     a
	JOIN	  cntr	c	ON	c.n	<= LENGTH (a.a_id)
)
SELECT    SUBSTR ( a_text
	         , 1
	         , LENGTH (a_text) - cut_length
	         ) 	AS cut_text
FROM      split_a_id
ORDER BY  a_text
,     	  cut_text	DESC
;

Now that you're dealing with multiple rows, you need a PARTITION BY clause in the analytic SUM function.

Thanks for including the CREATE TABLE and INSERT statements.
Please format your code, and post it between

 tags so this site won't remove any spaces.
The link was a good idea, but it seems to be a link to the wrong thread.

Edited by: Frank Kulash on Nov 17, 2009 2:46 PM
Commented out 2 line I forgot to delete after testing.

Marked as Answer by Ludy · Sep 27 2020

Ludy

Thanks Frank Kulash,
now got better understanding in using the LEVEL in CONNECT BY.
Now things are getting clearer to me.

sure will post code between

 tags, and sorry about the link.

Aketi Jyuuzou

I like recursive with clause B-)
I do Not have Oracle11gR2
Therefore I made below solution using PostgreSQL8.4 :8}

CREATE TABLE TTT(ID text,Val text);
INSERT INTO TTT(ID,Val) VALUES('13233424','ABCDEFGHIJKLMNOPQRSTUV');
INSERT INTO TTT(ID,Val) VALUES('13233424','WXYZABCDEFGHIJKLMNOPQR');

with recursive rec(ID,Val,LV,cuts) as(
select ID,Val,1   ,substr(ID,1,1)    from TTT
union all
select ID,Val,LV+1,substr(ID,LV+1,1) from rec
 where LV < length(ID))
select substr(Val,1,(sum(cuts::integer) over(partition by Val order by LV))::integer) as CUT_TEXT
  from rec
order by Val,LV desc;

       cut_text
-----------------------
ABCDEFGHIJKLMNOPQRSTUV
ABCDEFGHIJKLMNOPQR
ABCDEFGHIJKLMNOP
ABCDEFGHIJKL
ABCDEFGHI
ABCDEF
ABCD
A
WXYZABCDEFGHIJKLMNOPQR
WXYZABCDEFGHIJKLMN
WXYZABCDEFGHIJKL
WXYZABCDEFGH
WXYZABCDE
WXYZAB
WXYZ
W

I like model clause solution too :D

1 - 3

Locked Post

New comments cannot be posted to this locked post.

Locked on Dec 16 2009

Added on Nov 17 2009

3 comments

1,092 views

SQL & PL/SQL

SQL work for single row and not multiple

Comments

Post Details