HQL 的语法：select a from a where a=3 or select b from b whereb=

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HQL 的语法：select a from a where a=3 or select b from b whereb=2 要怎么写?

java.lang.NullPointerException 空指针异常,肯定是在你的代码中引用了null值的对象.
你这里的问题就是list的值为null了,出现这种情况,要么就是你的查询语句有问题,要么就是满足你查询条件的结果记录为0;
解决办法一、确认一下,你的column_id应该是你用hibernate生成的bean类的属性名（columnId）,而不是在你的表中的字段名,要特别注意一下这一点；
解决办法二、仔细确认一下你的数据里面,有没有满足条件的记录.

select * into b from a where 11 select A,B,C,D=(select count(*) from 表 where c=a.a and b=a.b select ** from A where A.id in (select id from B where ****) select distinct A.* from A,B where A.id = B.g_id and A.fwzid select * from a union select * from b 能详细说下么 SQL语句理解 select * from B where (select count(1) as num from A select A.a,b,c,d from A,B where A.a=B.a and f='1' select count(*) from v$process a,v$session b where a.addr = sql 中 select * from A left join B on A.id=B.id where A.id=?如 String sql = "select * from tb_consumer where account='" + a select count(*) as total from ddcm_news where key=a vb 如select * from a where b=' "+###1+" '的语句怎么写才可以筛选两个词