hibernate执行sql

博客分类：
• hibernate

SQL Hibernate 

1.执行sql，返回一个结果集，适用查询一个字段并返回一条记录

public Long findSeqTbTest() {
    String sql = "select SEQ_TB_TEST.nextval from dual";
    SQLQuery query = this.getSession().createSQLQuery(sql);
    String str = query.uniqueResult().toString();
    return Long.valueOf(str);
}

//获取表中最小的id
String sql = "select min(a.employeeid) from Emplyees a";
Long id = (Long) session.createQuery(sql).uniqueResult();

//获取数据库时间mysql
String sql = "select now() from dual";
String time =  session.createSQLQuery(sql).uniqueResult().toString();

2.删除、更新等操作，这里参数是从0开始的

public void deleteTbTest(Long id) {
    String hql = "DELETE FROM TbTest WHERE ID = ?";
    this.getSession().createQuery(hql).setLong(0, id).executeUpdate();
}

public void updateTbTest(Date date, boolean flag) {
    String sql = "update tb_test set t_name=? where t_status!=1 and t_date" + (flag ? "<?" : "=?");
    SQLQuery query = this.getSession().createSQLQuery(sql);
    query.setString(0,flag ? "hello": "hi").setDate(1, date).executeUpdate();
}

3.执行sql，查询单表中多条数据

//尽量避免适用"*"
String sql = "select * from employee e where e.valid=1 and not exists (select employeeid from attendance a where a.employeeid=e.employeeid and a.date = ?)";
SQLQuery query = getSession().createSQLQuery(sql);
query.addEntity(Employee.class).setDate(0, day);
List<Employee> retList = query.list();

4.查询多表

String hql = "select new map(dept.deptID as deptID,dept.depNo as deptNo,dept.deptName as deptName,emp.empName as empName,emp.empID as empID,emp.empAge as age,emp.empNo as empNo) from Department dept ,Employee emp where dept.depID = emp.depID and emp.empName = ? and emp.sex = ?";
return getHibernateTemplate().find(hql, new Object[] { name, sex });

每个字段都保存在map中（key是字段名，value是此字段的值如：[{empID=1,empName=leona,...},...]）

5.查询多表

String sql = "select dept.deptID as deptID,dept.depNo as deptNo,dept.deptName as deptName,emp.empName as empName,emp.empID as empID,emp.empAge as age,emp.empNo as empNo,emp.birthday as birthday from Employee emp LEFT JOIN Department dept on dept.depID = emp.depID where empName = ?";
        return (List<EmpBean>) this.getSession()
            .createSQLQuery(sql)
            .addScalar("deptID", Hibernate.STRING)
            .addScalar("deptNo", Hibernate.STRING)
            .addScalar("deptName", Hibernate.STRING)
            .addScalar("empName", Hibernate.STRING)
            .addScalar("empID", Hibernate.STRING)
            .addScalar("age", Hibernate.LONG)
            .addScalar("birthday", Hibernate.DATE)
            .addScalar("empNo", Hibernate.STRING)
            .setString(0, empName)
            // 将结果集映射为EmpBean对象
            .setResultTransformer(
                    Transformers.aliasToBean(EmpBean.class))
            .list();

String hql = "from Attendance att where att.employeeid = ? and att.date =? ";
List<Attendance> list = this.getHibernateTemplate().find(hql,
new Object[] { employeeid, workDay });
if (null != list && !list.isEmpty()) {
return list.get(0);
}


String queryString = "FROM Attendance a WHERE a.employeeid=? AND DATE_FORMAT(a.date,'%Y-%m')=DATE_FORMAT(?,'%Y-%m') ORDER BY a.teamname";
Query queryObject = getSession(). createQuery(queryString);
queryObject.setParameter(0, id);
queryObject.setParameter(1, date);
return queryObject.list();

Session session = getSession();
session.clear();
getSession().saveOrUpdate(transientInstance);

startBatch()的用法
public class LocalDaoImpl extends SqlMapClientDaoSupport implements LocalDao {

    public void insertBuNaTaxBatLst(final PaginatedList list)
    {
         getSqlMapClientTemplate().execute(new SqlMapClientCallback() {
                public Object doInSqlMapClient(SqlMapExecutor executor)
                        throws SQLException {
                    executor.startBatch();
                    // do some iBatis operations here
                    for(int i=0,count=list.size();i<count;i++)
                    {   
                        executor.insert("insertBuNaTaxBatLst", list.get(i));
                        if (i % 50 == 0) {
                            System.out.println("----" + i);//没有意义只为测试
                        }
                    }
                    executor.executeBatch();
                    return null;
                }
            });
    }