What can I apply as function?
Query:
Select x, f(y) from table where y like '%ab%cd%ef';
sample table(y is sorted alphabatically)
x. y
1 ab
2 ab,cd
3 cd,ef
4 ab,ef,gh,yu
5 de,ef,rt
Expected Output:
Output:
x y
1 ab
2 ab,cd
3 cd,ef
4 ab,ef
5 ef
Use regexp_substr function with connect by level expressions as
with tab(x,y) as
(
select 1,'ab' from dual union all
select 2,'ab,cd' from dual union all
select 3,'cd,ef' from dual union all
select 4,'ab,ef,gh,yu' from dual union all
select 5,'de,ef,rt' from dual
), tab2 as
(
Select x, regexp_substr(y,'[^,]+',1,level) as y
from tab
connect by level <= regexp_count(y,',') + 1
and prior x = x
and prior sys_guid() is not null
), tab3 as
(
select x, y
from tab2
where y like '%ab%'
or y like '%cd%'
or y like '%ef%'
)
select x, listagg(y,',') within group (order by y) as y
from tab3
group by x;
X Y
1 ab
2 ab,cd
3 cd,ef
4 ab,ef
5 ef
Follow comments written within the code.
SQL> with test (x, y) as
2 -- your sample table
3 (select 1, 'ab' from dual union all
4 select 2, 'ab,cd' from dual union all
5 select 3, 'cd,ef' from dual union all
6 select 4, 'ab,ef,gh,yu' from dual union all
7 select 5, 'de,ef,rt' from dual
8 ),
9 srch (val) as
10 -- a search string, which is to be compared to the sample table's Y column values
11 (select 'ab,cd,ef' from dual),
12 --
13 srch_rows as
14 -- split search string into rows
15 (select regexp_substr(val, '[^,]+', 1, level) val
16 from srch
17 connect by level <= regexp_count(val, ',') + 1
18 ),
19 test_rows as
20 -- split sample values into rows
21 (select x,
22 regexp_substr(y, '[^,]+', 1, column_value) y
23 from test,
24 table(cast(multiset(select level from dual
25 connect by level <= regexp_count(y, ',') + 1
26 ) as sys.odcinumberlist))
27 )
28 -- the final result
29 select t.x, listagg(t.y, ',') within group (order by t.y) result
30 from test_rows t join srch_rows s on s.val = t.y
31 group by t.x
32 order by t.x;
X RESULT
---------- --------------------
1 ab
2 ab,cd
3 cd,ef
4 ab,ef
5 ef
SQL>
