I have a rfc structure say a,bc[],d[],i want to perform crud operations

I have a rfc structure say a,bc[],d[],i want to perform crud operations for it do i have to create multiple entities and entity sets?Also if yes is mapping through map to data source possible or does this need abap coding,what would i have association key ?What is complex entity in my case it clubs items like a,b,c into the complex entity automatically