自己实现jdbc--有空再来改进-CFANZ编程社区

自己实现jdbc--有空再来改进

import java.sql.Connection; 

import java.sql.DriverManager; 

import java.sql.ResultSet; 

import java.sql.ResultSetMetaData; 

import java.sql.SQLException; 

import java.sql.Statement; 

import java.util.ArrayList; 

import java.util.HashMap; 

import java.util.List; 

import java.util.Map; 



public class JDBCTest { 


 public static void main(String[] args) throws SQLException{ 

 Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8", "root", "yang"); 

 Statement st = conn.createStatement(); 

 //执行事务 

 int j = st.executeUpdate("INSERT INTO EMP VALUES (55,'yang','22')"); 

 //执行查询 

 ResultSet rs= st.executeQuery("SELECT * FROM EMP"); 

// System.out.println("i:"+"rs:"+rs.getRow()); 


 //得到结果集(rs)的结构信息，比如字段数、字段名等   

 ResultSetMetaData md = rs.getMetaData(); 

 //返回此 ResultSet 对象中的列数 

        int columnCount = md.getColumnCount();    

        

        List list = new ArrayList();   

        Map rowData = new HashMap(); 

        

        //ResultSet 光标最初位于第一行之前； 

        //rs.next() 光标向下移动一行,得到每一列的值 

 while (rs.next()) { 

 System.out.println("rs:" + rs.getRow()); 

 rowData = new HashMap(columnCount); 

 for (int i = 1; i <= columnCount; i++) { 

 rowData.put(md.getColumnName(i), rs.getObject(i)); 

 } 

 list.add(rowData); 

 }  

        

        System.out.println("list:" + list.toString());   


 conn.close(); 

 } 


}