create or replace type acc_type as object
(acc varchar2(50))
/

create or replace type acc_table as table of acc_type
/

create or replace function str2table (acc_str in varchar2) return acc_table pipelined
is
v_str varchar2(30000) := acc_str;
v_acc varchar2(30);
v_acc_end pls_integer;
begin
loop
v_acc_end := instrb(v_str,',');
exit when (v_acc_end=0 or v_str is null);
v_acc := substrb(v_str,1,v_acc_end-1);
v_str := ltrim(v_str,v_acc);
v_str := ltrim(v_str,',');
pipe row(acc_type(rtrim(v_acc,';')));
end loop;
return;
end;
/

SQL> select * from table(str2table('TEST1,TEST1,12,123,55,99MOON,'));

ACC
--------------------------------------------------
TEST1
TEST1
12
123
55
99MOON

6 rows selected.

SQL>

要是加上分隔符作为输入参数就更具有通用性了

v_str := ltrim(v_str,v_acc);
好像有点问题，如果有连续两个相同的记录，就一起被删掉了