blank in query - cannot return results

Hello,

PostgreSQL 8.3.18 on x86_64-linux-gnu, query:

select * from table_name where col1 = 'Abc, test';
select * from table_name where col1 ilike '%Abc, test%';

NO result returned.

But run:
select * from table_name where col1 ilike '%Abc,%test%'; -- remove blank

Result is returned.

PSQL terminal encoding: unicode (UTF-8). From both terminal and db,
values shows/and displayed as "Abc, test".

But " " space/blank in where section cannot return query result.

Can someone tell why may cause the issue please?

Thanks a lot!