QueryRunner的使用（轉載）

QueryRunner的使用(轉載點擊看原文)

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

}
src目錄下c3p0-config.xml

 

從數據庫中取count(*)數據

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

 

取一條數據   其中表的字段名字和類的名字要對應相同

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

取集合數據List<>返回    其中表的字段名字和類的名字要對應相同

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

插入

QueryRunner runner= new QueryRunner(JdbcUtil.getDataSource());
        String sql ="insert into topic(name,author,content,time,type_id) values(?,?,?,?,?)";
        Object[] params={topic.getName(),topic.getAuthor(),topic.getContent(),topic.getTime(),topic.getTypeId()};
        try {
            //事務開始
            runner.update(sql,params);
            //事務提交
        } catch (SQLException e) {
            e.printStackTrace();
            //事務回滾
            throw e;
        }

更新

QueryRunner runner= new QueryRunner(JdbcUtil.getDataSource());
        String sql ="update topic set name=? , content=? , time=? where id= ?";
        Object[] params={topic.getName(),topic.getContent(),topic.getTime(),topic.getId()};
        try {
            //事務開始
            runner.update(sql,params);
            //事務提交
        } catch (SQLException e) {
            e.printStackTrace();
            //事務回滾
            throw e;
        }