How to query by page from to table by Hibernate?
I create 3 tables by Hibernate, how to return a List<task>
when set task_status
= ? and set create_user_id
= ?, task_status
in "dotask" table, create_user_id
in task
table.
How to write the "HQL"? Here is mine, but I can't make it true with it:
String hql="from task t left join dotask d on d.task_status = ? and t.create_user_id = ? limit ?, ?";
Query query=sess.createQuery(hql);
query.set(0,1);
...
query.set(4,2);
List<Task> lt=query.list();
The task.hbm.xml follows:
<class name="com.model.Task" table="task" >
<id name="id">
<generator class="native"/>
</id>
<property name="name" />
...
...
<set name="lu" table="dotask" cascade="save-update" lazy="true">
<key column="task_id"></key>
<many-to-many class="com.model.User" column="user_id"></many-to-many>
</set>
</class>
And the tables:
CREATE TABLE `dotask` (
`id` int(11) NOT NULL auto_increment,
`user_id` int(11) NOT NULL,
`task_id` int(11) NOT NULL,
`task_status` int(11) NOT NULL default '0',
PRIMARY KEY (`id`),
KEY `FKB0F704903D43702C` (`user_id`),
KEY `FKB0F70490EA675DEC` (`task_id`),
CONSTRAINT `FKB0F704903D43702C` FOREIGN KEY (`user_id`) REFERENCES `users` (`id`),
CONSTRAINT `FKB0F70490EA675DEC` FOREIGN KEY (`task_id`) REFERENCES `task` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;
CREATE TABLE `task` (
`id` int(11) NOT NULL auto_increment,
`name` varchar(128) NOT NULL,
`create_user_id` int(11) NOT NULL,
`create_time` date NOT NULL,
`end_time` date default NULL,
`limit_time` date NOT NULL,
`day` int(11) default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
CREATE TABLE `users` (
`id` int(11) NOT NULL auto_increment,
`departmentId` int(11) default NULL,
`name` varchar(50) default NULL,
`password` varchar(50) default NULL,
`sex` char(2) default NULL,
`birthday` date default NULL,
`address` va开发者_C百科rchar(200) default NULL,
`phone` varchar(100) default NULL,
`mobile` varchar(100) default NULL,
`remark` varchar(255) default NULL,
`login` varchar(50) default NULL,
`email` varchar(200) default NULL,
`active` int(11) default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=20 DEFAULT CHARSET=utf8;
Try this instead (not sure because you didn't show the object model and didn't describe all relations):
SELECT t
FROM Task t LEFT JOIN t.dotask d WITH d.task_status = ?
WHERE t.create_user_id = ?
And use setMaxResults()
and setFirstResult()
to limit the results in a portable way.
References
- Hibernate Core Reference Guide
- 14.3. Associations and joins
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