Read material data residing in MARA

Hello,

To create a purchase requistion from an external application, I used RFC.

But I have to read material data first, so I read them from MARA table using database queries. But, sometimes when I try to create a requistion, I get a message telling me that the material is not activated.

I tried to read materials using BAPI_MATERIAL_GET_DETAIL, BAPI_MATERIAL_GET_ALL and BAPI_MATERIAL_GETALL but all of those functions module require a material number as input and I want to get all materials.

How can I check if a material is active using database queries ? Or is there any function module that I can use to read all materials without putting material number as input?

Thanks.