dbutils的使用Demo

首先了解一下

　　　　Queryrunner.query    —————只可以执行select语句。

　　　　Queryrunner.update  —————只可以接收update,delte,insert语句

　　　　BeanHandler          ——————返回一个 Bean，结果封装到Bean。只查询第一行。适合根据id查询唯一的一行
　　　　BeanListHandler     ——————返回List<Bean>所有行，都封装到List，适合于查询多个结果

　　　　MapHandler           ——————与BeanHandler应，只返回第一行，封装成Map类型　－　也适合于查询一个结果集的    适合于关联查询，且没有匹配的Bean。
　　　　MapListHandler      ——————与BeanListHandler对应，返回所有，封装成List<Map>类型

　　　　ScalarHandler        ——————标量- 用于select count(1)|sum|avg|max …一些聚合函数

Demo（MyDataSource.getDataSource() —— 获取 DataSource）

插入数据

@org.junit.Test
    public void Query1() throws Exception
    {
        QueryRunner runner=new QueryRunner(MyDataSource.getDataSource());
        System.out.println(MyDataSource.getDataSource());
        //String sql="INSERT INTO users VALUES ('U002','tom','4321' )";
        //runner.update(sql);
        String sql="INSERT INTO users VALUES (?,?,? )";
        runner.update(sql,"U003","Jim","123456");
    }

更新数据

@org.junit.Test
    public void Query2() throws Exception
    {
        QueryRunner runner =new QueryRunner(MyDataSource.getDataSource());
        //String sql=" UPDATE users SET NAME='Kim' WHERE NAME='jim' ";
        //runner.update(sql);
        String sql=" UPDATE users SET NAME=? WHERE NAME=? ";
        runner.update(sql,"lily","Kim");
    }

删除数据

    @org.junit.Test
    public void Query3() throws Exception
    {
        QueryRunner runner=new QueryRunner(MyDataSource.getDataSource());
        //String sql="DELETE FROM users WHERE NAME='lily' ";
        //runner.update(sql);
        String sql="DELETE FROM users WHERE NAME=? ";
        runner.update(sql,"tom");
    }

查找数据

@org.junit.Test
    public void Query4() throws Exception
    {
        QueryRunner runner=new QueryRunner(MyDataSource.getDataSource());
        //String sql="SELECT * FROM users where id ='U002' ";
        //user u= runner.query(sql, new  BeanHandler<user>(user.class));
        
        String sql="SELECT * FROM users where id =? ";
        user u=runner.query(sql, new BeanHandler<user>(user.class),"U002");
        System.out.println(u);
    }

@org.junit.Test
    public void Query5() throws Exception
    {
        QueryRunner runner=new QueryRunner(MyDataSource.getDataSource());
        String sql="select * from users ";
        List<user> list= runner.query(sql, new BeanListHandler<user>(user.class));
        for(user u:list)
        {
            System.out.println(u);
        }
    }

@org.junit.Test
    public void Query6() throws Exception
    {
        QueryRunner runner =new QueryRunner(MyDataSource.getDataSource());
        String sql="select Id,name,Pwd from users ";
        Map<String, Object> map= runner.query(sql, new MapHandler());
        System.out.println(map.toString());
    }

    @org.junit.Test
    public void Query7() throws Exception
    {
        QueryRunner runner =new QueryRunner(MyDataSource.getDataSource());
        String sql="Select * from users ";
        List<Map<String , Object>> list= runner.query(sql, new MapListHandler());
        System.out.println(list);
    }

    @org.junit.Test
    public void Query8() throws Exception
    {
        QueryRunner runner =new QueryRunner(MyDataSource.getDataSource());
        String sql="select count(*) from Users ";
        Object obj=runner.query(sql, new ScalarHandler());
        int i=Integer.valueOf(obj.toString());
        System.out.println(i);
    }

导入包包括