Report jpql query with grater than of string

Hi ,
I have a report in jpql and I want generate a recordset with all record grater than and less than passed strings parameters.

For example I have this jpql
select e.Item as “Item”, e.description as “description”, e.supplier as “supplier”
from datastore_Item e where
(e.supplier >= ${supplier01da} AND e.supplier <= ${supplier01a})
order by e.supplier

If I pass as parameters of supplier from ‘F26’ to ‘F3’
the record set that display in the report is ‘F273’ to ‘F3’ and I don’t see record with supplier ‘F26’ that exists in database.
Why The jpql don’t take record with uqual condition?
How i can modify jpql query to have the right result?

Set up SQL logging as described here and check what SQL statement is generated. It may give you some clue.