Comments on: How to generate all strings of balanced parentheses in SQL http://oraqa.com/2008/06/16/how-to-generating-all-strings-of-balanced-parentheses-in-sql/ Oracle Question and Answer Mon, 19 Dec 2011 14:21:07 -0700 http://wordpress.org/?v=2.8.4 hourly 1 By: newkid http://oraqa.com/2008/06/16/how-to-generating-all-strings-of-balanced-parentheses-in-sql/comment-page-1/#comment-277 newkid Fri, 25 Jun 2010 14:13:07 +0000 http://oraqa.com/?p=259#comment-277 forgot to put code in the pre tag: <pre> variable input number exec :input :=5; WITH t (str,left_cnt,right_cnt) AS ( SELECT '(',1,0 FROM DUAL UNION ALL SELECT CAST(t.str||new_str AS VARCHAR2(20)) ,left_cnt + DECODE(new_str,'(',1,0) ,right_cnt + DECODE(new_str,')',1,0) FROM t,(SELECT '(' AS new_str FROM DUAL UNION ALL SELECT ')' AS new_str FROM DUAL) WHERE new_str = '(' AND left_cnt<5 OR new_str = ')' AND right_cnt<5 AND right_cnt<left_cnt ) SELECT * FROM T WHERE left_cnt=5 AND right_cnt=5; <pre> forgot to put code in the pre tag:

variable input number
exec :input :=5;

WITH
t (str,left_cnt,right_cnt) AS (
SELECT '(',1,0 FROM DUAL
UNION ALL
SELECT CAST(t.str||new_str AS VARCHAR2(20))
      ,left_cnt + DECODE(new_str,'(',1,0)
      ,right_cnt + DECODE(new_str,')',1,0)
 FROM t,(SELECT '(' AS new_str FROM DUAL UNION ALL SELECT ')' AS new_str FROM DUAL)
WHERE new_str = '(' AND left_cnt<5
      OR new_str = ')' AND right_cnt<5 AND right_cnt<left_cnt
)
SELECT * FROM T WHERE left_cnt=5 AND right_cnt=5;


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		By: newkid
		http://oraqa.com/2008/06/16/how-to-generating-all-strings-of-balanced-parentheses-in-sql/comment-page-1/#comment-276
		newkid
		Fri, 25 Jun 2010 14:12:23 +0000
		http://oraqa.com/?p=259#comment-276
		11GR2:

variable input number
exec :input :=5;

WITH
t (str,left_cnt,right_cnt) AS (
SELECT '(',1,0 FROM DUAL
UNION ALL
SELECT CAST(t.str||new_str AS VARCHAR2(20))
      ,left_cnt + DECODE(new_str,'(',1,0)
      ,right_cnt + DECODE(new_str,')',1,0)
 FROM t,(SELECT '(' AS new_str FROM DUAL UNION ALL SELECT ')' AS new_str FROM DUAL)
WHERE new_str = '(' AND left_cnt<5
      OR new_str = ')' AND right_cnt<5 AND right_cnt<left_cnt
)
SELECT * FROM T WHERE left_cnt=5 AND right_cnt=5;
		11GR2:


variable input number

exec :input :=5;


WITH

t (str,left_cnt,right_cnt) AS (

SELECT ‘(’,1,0 FROM DUAL

UNION ALL

SELECT CAST(t.str||new_str AS VARCHAR2(20))

      ,left_cnt + DECODE(new_str,’(',1,0)

      ,right_cnt + DECODE(new_str,’)',1,0)

 FROM t,(SELECT ‘(’ AS new_str FROM DUAL UNION ALL SELECT ‘)’ AS new_str FROM DUAL)

WHERE new_str = ‘(’ AND left_cnt<5

      OR new_str = ‘)’ AND right_cnt<5 AND right_cnt<left_cnt

)

SELECT * FROM T WHERE left_cnt=5 AND right_cnt=5;

]]>