TO_INT SQL HANA

Hi,

I have this kind of query :

SELECT *

FROM "@Table"

WHERE TO_INT("Field") <= TO_INT('1') OR ifnull("Field",'') = ''

the Field is a CHAR(2) , when run query on HANA STUDIO it's returned an error, if take off TO_INT from the query the result is showed.

i need TO_INT because without 10 <= 2 it's true.