4.批处理的基本用法

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;



public class Demo_main {

	public static void main(String[] args){
		PreparedStatement ps = null;
		Connection c =null;
			try {
				//加载驱动类
				Class.forName("com.mysql.jdbc.Driver");
				//建立连接
				c = DriverManager.getConnection("jdbc:mysql://localhost:3306/jdbc的使用","root","root");
				//执行SQL语句
		
			    String str ="select * from student where age>?";
				ps = c.prepareStatement(str);
				ps.setObject(1, 18);
				ResultSet rs = ps.executeQuery();
				while(rs.next()) {
					System.out.println("id="+rs.getInt(1)+"   姓名="+rs.getString(2)+"   age="+rs.getString(3));
				}
								
			} catch (ClassNotFoundException e) {
				e.printStackTrace();
			} catch (SQLException e) {
				e.printStackTrace();
			}finally {
//关闭,每一个关闭之前都要判断是否为空,且要分开捕获其异常,关闭顺序为早开起的后关闭,后开始的早关闭
				try {
					if(ps != null) {
						ps.close();
						}
				} catch (SQLException e) {
					e.printStackTrace();
				}
				try {
					if(c != null) {
						c.close();						
					}
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}

			
			
	}

}