JDBC编程步骤
1.注册驱动
Class.forname("com.mysql.jdbc.Driver");
2.获取链接
Connection con=DriverManager.getConnection(url,user,password);
3.创建statement对象
Statement st=con.createment();
4.发送sql并且执行
ResultSet rs=st.executeQuery();
5.遍历结果集
while(rs.next){
...
}
6.释放资源,放在finally中
案例:
public static void main(String[] args) { //获取连接 Connection con = null; //创建statement对象 Statement statement = null; ResultSet rs = null; try { //1.注册驱动 Class.forName("com.mysql.jdbc.Driver"); con = DriverManager.getConnection("jdbc:mysql://localhost:3306/day09", "root", "123"); statement = con.createStatement(); //发送并执行sql String sql = "select * from user"; rs = statement.executeQuery(sql); //遍历 while(rs.next()){ String id = rs.getString("id"); String name = rs.getString(2); int age = rs.getInt(3); System.out.println(id+"+++"+name+"++++"+age); } } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ //释放资源 if(rs!=null){ try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if(statement!=null){ try { statement.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if(con!=null){ try { con.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
今天要比昨天好