I have the following select statement...
select catalogue_id product_id from /itcp/prod into table product_keys where catalogue_id in me->catalogue_id_range and product_id in me->product_id_range and deleted eq abap_false.
The issue is it's only returning product_id's matching the case of my front-end query (sap gateway)., which is.. prodtest.
Products/$count?$filter=substringof(%27prodtest%27,productId).
Using get_filter_select_options( ), Its comes into the backend thus:

The behavior I was expecting with the CP operator is for it to be case insensitive, and should be returning, for example prodtest, PRODTEST or any combination of uppercase and lower case characters.
However, at the moment it is case-senstive and only returns items that exactly match the query of prodtest.
Does anyone have an explanation, or suggestions to make the query case insensitive?