QueryRunner的使用

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public class JdbcUtil {
private static ComboPooledDataSource dataSource =new ComboPooledDataSource();
public static ComboPooledDataSource getDataSource()
{
return dataSource;
}

}

src目录下c3p0-config.xml

从数据库中取count(*)数据

1         int topicNum=0;2         QueryRunner runner= new QueryRunner(JdbcUtil.getDataSource());3         String sql ="select count(*) from topic where type_id= ? order by time desc";4         Object[] params={typeId};5         topicNum=(int)(long) runner.query(sql,new ScalarHandler(),params);6         return topicNum;

取一条数据其中表的字段名字和类的名字要对应相同

1         Topic newlyTopic=null;2         QueryRunner runner= new QueryRunner(JdbcUtil.getDataSource());3         String sql ="select * from topic where type_id= ? order by time desc";4         Object[] params={typeId};5         newlyTopic= runner.query(sql,new BeanHandler<Topic>(Topic.class),params);6         return newlyTopic;

取集合数据List<>返回其中表的字段名字和类的名字要对应相同

1         List<Topic> topicList=new ArrayList<Topic>();2         QueryRunner runner= new QueryRunner(JdbcUtil.getDataSource());3         String sql ="select * from topic where type_id= ? order by time desc";4         Object[] params={typeId};5         topicList=runner.query(sql, new BeanListHandler<Topic>(Topic.class),params);6         return topicList;

插入

 1         QueryRunner runner= new QueryRunner(JdbcUtil.getDataSource()); 2         String sql ="insert into topic(name,author,content,time,type_id) values(?,?,?,?,?)"; 3         Object[] params={topic.getName(),topic.getAuthor(),topic.getContent(),topic.getTime(),topic.getTypeId()}; 4         try { 5             //事务开始 6             runner.update(sql,params); 7             //事务提交 8         } catch (SQLException e) { 9             e.printStackTrace();10             //事务回滚11             throw e;12         }

更新

 1         QueryRunner runner= new QueryRunner(JdbcUtil.getDataSource()); 2         String sql ="update topic set name=? , content=? , time=? where id= ?"; 3         Object[] params={topic.getName(),topic.getContent(),topic.getTime(),topic.getId()}; 4         try { 5             //事务开始 6             runner.update(sql,params); 7             //事务提交 8         } catch (SQLException e) { 9             e.printStackTrace();10             //事务回滚11             throw e;12         }

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