Created by Jerry Wang, last modified on Sep 22, 2015
使用如下url 进行测试：
https://:4080/sap/opu/odata/sap/CRM_OPPORTUNITY/Opportunities?KaTeX parse error: Expected 'EOF', got '&' at position 22: …=Id,Description&̲top=1
返回结果只包含request的id和description：
how is OData url select option implemented in the backend 但是在backend返回给gateway的entity response里，包含了整个opp header的所有数据：
how is OData url select option implemented in the backend how is OData url select option implemented in the backend 那么这个selection的filter只能是在gateway上做的：
how is OData url select option implemented in the backend how is OData url select option implemented in the backend how is OData url select option implemented in the backend how is OData url select option implemented in the backend how is OData url select option implemented in the backend lo_expand_select包含我们url传入的id和description信息：
how is OData url select option implemented in the backend how is OData url select option implemented in the backend how is OData url select option implemented in the backend how is OData url select option implemented in the backend how is OData url select option implemented in the backend 在这里指定只将id和description这两个property写回http response里：
how is OData url select option implemented in the backend 
