Hibernate使用hql和sql查询

一般情况下，程序里写了实体类（TestEntity.java）以及实体类和hibernate的映射文件（TestEntity.hbm.xml），那么在写操作数据库语句时，会使用hql，直接操作实体类，很方便且不容易出错，写法：

一般查询：可以一次写完整个hql语句，需要传递的参数预留出位置，后面用query.set*()放进去，再执行this.execFoQuery(query)就可以了：

public class TestDao extends FoHibernateDaoSupport implements ITestDao{
public TestEntity findTestListById(Integer id) {
FoHQLQuery query = new FoHQLQuery("from TestEntity a where a.testId=:ID");
query.setLong("ID", id);
return (TestEntity) this.execFoQuery1(query);
}
}

分页查询，是不是很方便，只要告诉它每页多少条，第多少页就可以，前端搭配EasyUI等框架，写起来很方便，使用execFoPageQuery：

public class TestDao extends FoHibernateDaoSupport implements ITestDao{
public FoPage findTestList(TestEntity entity, int pageNum, int pageSize) {
FoHQLQuery query = new FoHQLQuery();
String hql = "from TestEntity a  where 1=1 ";
if (entity.getId()!=null && !"".equals(entity.getId().trim())){
hql=hql +" and a.Id=:ID";
query.setString("ID", entity.getId());
}
if ((entity.getStartTime()!=null)&&(!entity.getStartTime().equals(""))){
hql=hql +" and a.startTime >='"+entity.getStartTime()+"'";
}
if ((entity.getEndTime()!=null)&&(!entity.getEndTime().equals(""))){
hql=hql +" and a.startTime <='"+entity.getEndTime()+"'";
}
hql += " order by a.startTime desc";
query.setHQL( hql );
query.setPageNum( pageNum );
query.setpageSize( pageSize );
return this.execFoPageQuery( query );
}
}

保存删除对象，直接保存对象，是不是很方便，不用像写sql那样把每个字段insert进去，使用this.getHibrenateTemplete()：

public class TestDao extends FoHibernateDaoSupport implements ITestDao{
public void saveTest(TestEntity entity) {
this.getHibernateTemplate().save(entity);
}
public void delTest(TestEntity entity) {
this.getHibernateTemplate().delete(entity);
}
}

但是，并不是所有的查询会需要实体类的映射，假如有一些情况下，直接使用sql会更方便些，那现有的工程里的Hibernate怎么执行sql呢：

package com.test.dao;
import java.util.List;
import com.sys.dao.FoHibernateDaoSupport;

public class SqlTestDao extends FoHibernateDaoSupport  {
public int findTotalNum(String startTime) {
String sql = "select t.Id from OtherEntity t where t.startTime >= '" +
startTime + "' and t.responseTime is not null";
List list = (List)this.getHibernateTemplate().find(sql);
if(list == null){
return 0;
}
return list.size();
}
}

其中，execFoQuery()是：

package com.sys.dao;
import java.sql.SQLException;
import java.util.List;
import org.hibernate.Hibernate;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.SQLQuery;
import org.hibernate.Session;
import org.springframework.orm.hibernate3.HibernateTemplate;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

public class FoHibernateDaoSupport extends HibernateDaoSupport{
public FoPage execFoPageQuery(FoQuery foQuery){
if (foQuery instanceof FoHQLQuery){
return execFoPageHQLQuery((FoHQLQuery)foQuery);
}if (foQuery instanceof FoSQLQuery){
return execFoPageSQLQuery((FoSQLQuery)foQuery);
}if (foQuery instanceof FoNamedQuery){
return execFoPageNamedQuery((FoNamedQuery)foQuery);
}
return null;
}

public List execFoQuery(FoQuery foQuery){
if (foQuery instanceof FoHQLQuery){
return execFoHQLQuery((FoHQLQuery)foQuery);
}if (foQuery instanceof FoSQLQuery){
return execFoSQLQuery((FoSQLQuery)foQuery);
}if (foQuery instanceof FoNamedQuery){
return execFoNamedQuery((FoNamedQuery)foQuery);
}
return null;
}

public int execFoUpdate(FoQuery foQuery){
Integer i = null;
if (foQuery instanceof FoHQLQuery){
i = execFoHQLUpdate((FoHQLQuery)foQuery);
} else if (foQuery instanceof FoSQLQuery){
i = execFoSQLUpdate((FoSQLQuery)foQuery);
} else if (foQuery instanceof FoNamedQuery){
i = execFoNamedUpdate((FoNamedQuery)foQuery);
}
return i.intValue();
}

public Object execFoQuery1(FoQuery foQuery){
List list = execFoQuery(foQuery);
if ((list == null) || (list.size() == 0)) {
return null;
}
return list.get(0);
}

private FoPage execFoPageHQLQuery(FoHQLQuery foQuery){
return (FoPage)getHibernateTemplate().execute(
new HibernateCallback(foQuery){
public Object doInHibernate(Session session) throws HibernateException{
FoPage foPage = new FoPage();
int nPageSize = this.val$foQuery.getPageSize();
if (nPageSize <= 0) {
nPageSize = 10;
}
int nPageNum = this.val$foQuery.getPageNum();
if (nPageNum <= 0) {
nPageNum = 1;
}
foPage.setPageSize(nPageSize);
foPage.setPageNum(nPageNum);
int totalCount = 0;
if (this.val$foQuery.getCountHQL() != null){
totalCount = ((Number)this.val$foQuery.fillQueryStmt(
session.createQuery(this.val$foQuery.getCountHQL()))
.uniqueResult()).intValue();
foPage.setTotalRecordCount(totalCount);
}else{
throw new HibernateException("没有找到统计总数的HQL");
}
if ((nPageNum - 1) * nPageSize >= totalCount){
foPage.setPageNum(foPage.getPageCount());
nPageNum = foPage.getPageNum();
}
foPage.setDataList(
this.val$foQuery.fillQueryStmt(session.createQuery(this.val$foQuery.getHQL()))
.setFirstResult((nPageNum - 1) * nPageSize).setMaxResults(nPageSize)
.list());
return foPage;
}
});
}
}