JDBC13 ORM02 Map封装

Posted 2022-09-27 code-fun

用Map封装一条信息

conn=Utils.getConn();
                ps=conn.prepareStatement("select Empname,birthday,salary from emp where id=?");
                ps.setObject(1, 1);
                rs=ps.executeQuery();
                while(rs.next()) 
                    row.put("Empname",rs.getObject(1) );
                    row.put("birthday", rs.getObject(2));
                    row.put("salary", rs.getObject(3));
                
                for(String key:row.keySet()) 
                    System.out.print(row.get(key));
                

用List盛放Map 存储多条信息

conn=Utils.getConn();
            ps=conn.prepareStatement("select Empname,birthday,salary from emp where id>?");
            ps.setObject(1, 1);
            rs=ps.executeQuery();
            while(rs.next()) 
                Map<String,Object>row=new HashMap<>();
                row.put("Empname",rs.getObject(1) );
                row.put("birthday", rs.getObject(2));
                row.put("salary", rs.getObject(3));
                list.add(row);
            
            for(Map<String,Object> map:list) 
                for(String key:map.keySet()) 
                    System.out.print(map.get(key));
                
                System.out.println();