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   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 }