Problems of GET_ENTITY&GET_ENTITYSET In Netweaver Gateway Odata

Hi All,

          I have two entities "WKXCC_COSTCENTER" and "WKXCC_USER".and I  want to associate them, WKXCC_COSTCENTER(1) , WKXCC_USER(n),and this is my codes:

After do that I back to visit my url,and I find no entry in it.

no entries:

what should I do to modify my codes?

Thanks in advance!!!!!