Simple to use Oracle Replace function

 

REPLACE (char, search_string [, replace_string]) If no replace_string variable value, when the found value search_string variables will be deleted

 

1. Replace

update EMAIL set MAILSUBJECT =replace(MAILSUBJECT,'UAT',REMARKS||' UAT') where docID='0000002955' and PARTINDEX!=0;

 

2. Do not set the third argument, equal to delete

--23 deleted
select replace ( 'abcdefg', ' abc') from dual;

result: