Hibernate Session 获取connection
由于最近一个项目要用到一条辅助的SQL ,hibernate里面的SQLQuery API 总的SQL语句不能包含 : 冒号, 固放弃Hibernate, 直接使用JDBC.
Hibernate3.3.2版本中getSession().connection()已被弃用，替代方法
SessionFactoryUtils.getDataSource(getSessionFactory()).getConnection()
原有方法
getSession().connection()
来自类org.springframework.orm.hibernate3.SessionFactoryUtils
例子：
java.sql.Connection c = null;
java.sql.PreparedStatement ps = null;
java.sql.ResultSet rs = null;
public List method(String sql) {
List ret = new ArrayList();
try {
c = SessionFactoryUtils.getDataSource(getSessionFactory()).getConnection();
ps = c.prepareStatement(sql);
rs = ps.executeQuery();
while(rs.next()) {
.....
}
ret.add(ro);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
close();
}
return ret;
}
我的demo
/**
*
*
* @author mjorcen
* @email [email protected]
* @dateTime Jul 4, 2014 5:43:05 PM
* @version 1
* @throws SQLException
*/
private void getTop() throws SQLException {
StringBuilder sb = new StringBuilder();
sb.append("SELECT X.COMMENT_ID, X.TOTAL_NO, X.ORDER_NO, IFNULL(X.ORDER_NO / X.TOTAL_NO, 1) AS PERCENTAGE_NO ");
sb.append("FROM (SELECT @rowNum := @rowNum + 1 AS ORDER_NO, @rowCount AS TOTAL_NO, t.COMMENT_ID, t.COMMENT_SPENDING ");
sb.append(" FROM T_SD_COMMENT t, (SELECT @rowNum := 0 ");
sb.append(" ) b, (SELECT @rowCount := ( ");
sb.append(" SELECT COUNT(*) ");
sb.append(" FROM T_SD_COMMENT ");
sb.append(" WHERE to_days(CREATE_TIME) >= to_days(now()) ");
sb.append(" ) ");
sb.append(" ) c ");
sb.append(" WHERE to_days(t.CREATE_TIME) >= to_days(now()) ORDER BY t.COMMENT_SPENDING ,t.COMMENT_ID ");
sb.append(" ) X ");
sb.append("WHERE X.COMMENT_ID = ? ");
Connection c = this.commentService.getSession().connection();
PreparedStatement ps = c.prepareStatement(sb.toString());
ps.setInt(1, this.paramComment.getCommentId());
ResultSet rs = ps.executeQuery();
if (rs.next()) {
System.out.println("COMMENT_ID = " + rs.getInt("COMMENT_ID"));
System.out.println("TOTAL_NO = " + rs.getInt("TOTAL_NO"));
System.out.println("ORDER_NO = " + rs.getInt("ORDER_NO"));
System.out.println("PERCENTAGE_NO = " + rs.getDouble("PERCENTAGE_NO"));
}
}
Hibernate API中让使用doWork(Work,work)，描述如下：
connection()
Deprecated. (scheduled for removal in 4.x). Replacement depends on need; for doing direct JDBC stuff usedoWork(org.hibernate.jdbc.Work); for opening a ‘temporary Session‘ use (TBD).
Work接口的execute()方法用于执行直接通过JDBC API来访问数据库的操作：
public interface Work {
// 直接通过JDBC API来访问数据库的操作
public void execute(Connection connection) throws SQLException;
}
Session的doWork(Work work)方法用于执行Work对象指定的操作，即调用Work对象的execute()方法。
Session会把当前使用的数据库连接传给execute()方法。
过程如下：
Transaction tx = session.beginTransaction();
// 定义一个匿名类，实现了Work接口
Work work = new Work() {
public void execute(Connection connection) throws SQLException {
// 通过JDBC API执行用于批量更新的SQL语句
PreparedStatement stmt = connection
.prepareStatement("update CUSTOMERS set AGE=AGE+1 "
+ "where AGE>0 ");
stmt.executeUpdate();
}
};
执行work
session.doWork(work); tx.commit();
当通过JDBC API中的PreparedStatement接口来执行SQL语句时，SQL语句中涉及到的数据不会被加载到Session的缓存中，因此不会占用内存空间。
Hibernate Session 获取connection