Getting rows that are having distinct id with bulk collect - Oracle - oracle

Question

I want to get the records that are having distinct member id using bulk collect.
My query is like below:
...
type members_nt is table of table2%rowtype;
members_bc members_nt;
...
select t2.* bulk collect
into members_bc
from table1 t1
,table2 t2
where t1.isn= t2.isn
and t1.customer= customer
and t1.insert_date between ... and ... );
t2 table has a column named member_id and what I want to get into members_bc is the rows having distinct member_id.
For example if my t2 table has something like this:
name | surname | account | member_id
john alby abc 123
john alby def 123
mary hale lkj 234
I want to bulk collect only
name | surname | account | member_id
john alby abc 123
mary hale lkj 234
or
name | surname | account | member_id
john alby def 123
mary hale lkj 234
It does not matter which one. But memberid must be unique in the members_bc.
How can I achieve this? Thank you.

Answer 1

Use the ROW_NUMBER() analytic function to give each row a number per member_id and then filter to only get the first row.
DECLARE
TYPE members_nt IS TABLE OF table2%ROWTYPE;
members_bc members_nt;
BEGIN
SELECT t2.name, t2.surname, t2.account, t2.member_id
BULK COLLECT INTO members_bc
FROM (
SELECT t2.*,
ROW_NUMBER() OVER ( PARTITION BY member_id ORDER BY ROWNUM ) AS rn
FROM table2 t2
) t2
WHERE rn = 1;
FOR i IN 1 .. members_bc.COUNT LOOP
DBMS_OUTPUT.PUT_LINE( members_bc(i).member_id || ' ' || members_bc(i).name );
END LOOP;
END;
/
outputs:
123 john
234 mary
db<>fiddle here

Answer 2

You can avoid "select *" and just enter the desired columns by creating a cursor for your select and then creating a %rowtype of the cursor.
Using #MT0 answer as baseline template.)
declare
cursor members_cur is
select t2.name, t2.surname, t2.account, t2.member_id
from ( select t2.name, t2.surname, t2.account, t2.member_id
, row_number() over ( partition by member_id order by rownum ) as rn
from table2 t2
) t2
where rn = 1;
type members_tt is table of members_cur%rowtype;
members_bc members_tt;
begin
open members_cur;
fetch members_cur
bulk collect into members_bc;
close members_cur;
for i in 1 .. members_bc.count
loop
dbms_output.put_line(members_bc(i).member_id || ' ' ||members_bc(i).name);
end loop;
end;

Answer 3

A simple option is to use aggregation, e.g.
select name,
surname,
min(account) as account, --> this
member_id
from ...
group by name, surname, member_id --> and this