Comments on: How to determine if the formula string contains balanced pairs of parentheses in SQL http://oraqa.com/2008/06/08/how-to-determine-if-the-formula-string-contains-balanced-pairs-of-parentheses-in-sql/ Oracle Question and Answer Thu, 20 Nov 2008 23:04:42 +0000 http://wordpress.org/?v=2.6.3 By: Frank Zhou http://oraqa.com/2008/06/08/how-to-determine-if-the-formula-string-contains-balanced-pairs-of-parentheses-in-sql/#comment-239 Frank Zhou Tue, 10 Jun 2008 14:20:08 +0000 http://oraqa.com/?p=258#comment-239 Gmyers, Your simpler method doesn't work, it didn't put all cases into consideration. For example when str_num = '1+)2+(3+4' SQL> select str_num, 2 case when length(replace(str_num,')')) = length(replace(str_num,'(')) 3 then 'T' else 'F' end bal 4 from ( select '1+)2+(3+4' str_num from dual); STR_NUM BAL --------- ----- 1+)2+(3+4 T The correct answer should be "F". Frank Gmyers,

Your simpler method doesn’t work,
it didn’t put all cases into consideration.

For example when str_num = ‘1+)2+(3+4′

SQL> select str_num,
2 case when length(replace(str_num,’)')) = length(replace(str_num,’('))
3 then ‘T’ else ‘F’ end bal
4 from ( select ‘1+)2+(3+4′ str_num from dual);

STR_NUM BAL
——— —–
1+)2+(3+4 T

The correct answer should be “F”.

Frank

]]> By: gmyers http://oraqa.com/2008/06/08/how-to-determine-if-the-formula-string-contains-balanced-pairs-of-parentheses-in-sql/#comment-238 gmyers Mon, 09 Jun 2008 23:27:42 +0000 http://oraqa.com/?p=258#comment-238 Or a simple select str_num, case when length(replace(str_num,')')) = length(replace(str_num,'(')) then 'T' else 'F' end bal from test Or a simple
select str_num,
case when length(replace(str_num,’)')) = length(replace(str_num,’('))
then ‘T’ else ‘F’ end bal
from test

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