QueryRunner的使用

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

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

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         }