select * from exampaper ; 
select * from dbo.exampaperblock
delete from exampaperblock where exampaperid not in(select id from exampaper );
select * from exampaper_random;
delete from exampaper_random where blockid not in(select id from exampaperblock)
select * from exampaperblockquestion;
delete from exampaperblockquestion where blockid not in(select id from exampaperblock)

Caused by: java.lang.NoClassDefFoundError: org/apache/openjpa/enhance/PersistenceCapable