用树形结构表示实体之间联系的模型是( )

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='29841' and id < 2421865 and id<>'2421865' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='29841' and id > 2421865 and id<>'2421865' order by id asc limit 5