Inconsistent datatypes: expected - got CLOB

Question

hi guys, i am currently doing a select from my table and in one of my selects I am doing a max() so therfore in the group by clause i have to group by every column that was not being used with max. As a result i get the error stated in the title of this thread. Would anyone know the reason why or how I can solve this problem.
Thanks.

Answer 1

Depending on how much data you are actually storing in your CLOB this might work for you:
create table my_table (my_num number, my_clob CLOB);
insert into my_table values (1, 'Hi there');
insert into my_table values (1, 'Hello');
insert into my_table values (2, 'Goodbye');
with data as (
select my_num, cast(substr(my_clob,1,4000) as varchar2(4000)) my_clob_varchar
from my_table
select my_num, max(my_clob_varchar)
from data
group by my_num;Result
MY_NUM     MAX(MY_CLOB_VARCHAR)
1     Hi there
2     Goodbye