REGEXP - How to exclude word

Question

Hi,
i wanted to know how to exclude a part of word when matching word.
For example i want to exclude all words that begins with 'bc_'
I tried a regular expression like '^(?!bc_).*' but it doesn't seem to work
Does anyone have an idea ?
Thx.

Answer 1

Hi,
Welcome to the forum!
Whenever you have a question, it helps if you post some sample data and the resutls you want from that data.
You can post the sample data in the form of a WITH clause, like Blushadow did, or as CREATE TABLE and INSERT statements:
CREATE TABLE     table_x
(      x_id     NUMBER (2)
,      txt     VARCHAR2 (30)
INSERT INTO table_x (x_id, txt) VALUES (1,  'bc_name');
INSERT INTO table_x (x_id, txt) VALUES (11, 'xxx');
INSERT INTO table_x (x_id, txt) VALUES (12, 'xxbc_xxx');
INSERT INTO table_x (x_id, txt) VALUES (13, 'bcxxx');When posting the results (or any formatted text) type these 6 characters:
\(all small letters, inside curly brackets) to keep this site from compressing the spaces.
Given the data above, are these the results you want?X_ID TXT NEW_TXT
1 bc_name new_name
11 xxx xxx
12 xxbc_xxx xxbc_xxx
13 bcxxx bcxxx
If so, you don't need regular expressions, and it will be more efficient not to use them:SELECT x_id
,     txt
,     CASE
     WHEN txt LIKE 'bc\_%' ESCAPE '\'
     THEN 'new_name'
     ELSE txt
     END          AS new_txt
FROM     table_x
ORDER BY x_id