下列哪一情形产生不当得利之债？（ ）

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SQL Error: select id,body,options from ***_enewstiku where sourceid='31904' and id < 2550667 and id<>'2550667' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='31904' and id > 2550667 and id<>'2550667' order by id asc limit 5