若关系R(H, L, M, P)的主键为全码（All-key),则关系R的主键应（）。

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SQL Error: select id,body,options from ***_enewstiku where sourceid='30131' and id < 2441867 and id<>'2441867' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='30131' and id > 2441867 and id<>'2441867' order by id asc limit 5