Remove Substring Occurrences in String

Question

I have a stirng in PL/SQL
"first text {a-start} first body {a-end} test1 {b-start} secondy body {b-end} test2
{c-start} third body {c-end} end text"
a) here {a-start},{a-end},etc.. are fixed values and these can be repeated
Declare
ret_val number (10) := 1;
begin
if ( ret_val = 1) then
output : first text first body test1 test2 end text
if (ret_val=2) then
output : first text test1 second body test2 end text
if (ret_val =3) then
output: first text test1 test2 third body end text
end if;
end;
Can anbody help me.
Thank You,
Regards
Prabhakar T

Answer 1

Quick and dirty:
  1  with v as (
  2  select 1 ret_val, 'first text {a-start} first body {a-end} test1 {b-start} '||
  3  'second body {b-end} test2 {c-start} third body {c-end} end text' str from dual union all
  4  select 2 ret_val, 'first text {a-start} first body {a-end} test1 {b-start} '||
  5  'second body {b-end} test2 {c-start} third body {c-end} end text' str from dual union all
  6  select 3 ret_val, 'first text {a-start} first body {a-end} test1 {b-start} '||
  7  'second body {b-end} test2 {c-start} third body {c-end} end text' str from dual
  8  )
  9  select case ret_val
10     when 1
11     then regexp_replace (
12        str,
13        '(^.+){a-start}(.+){a-end}(.+){b-start}(.+){b-end}(.+){c-start}(.+){c-end}(.+)$',
14        '\1\2\3\5\7'
15     )
16     when 2
17     then regexp_replace (
18        str,
19        '(^.+){a-start}(.+){a-end}(.+){b-start}(.+){b-end}(.+){c-start}(.+){c-end}(.+)$',
20        '\1\3\4\5\7'
21     )
22     when 3
23     then regexp_replace (
24        str,
25        '(^.+){a-start}(.+){a-end}(.+){b-start}(.+){b-end}(.+){c-start}(.+){c-end}(.+)$',
26        '\1\3\5\6\7'
27     )
28     end str
29* from v
SQL> /
STR
first text  first body  test1  test2  end text
first text  test1  second body  test2  end text
first text  test1  test2  third body  end text
3 rows selected.