Java 数据查询

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

import com.mysql.jdbc.Statement;

public class Demo {

	public static void main(String[] args)  {
		Connection connection = null;//链接接口
		Statement statement = null;//发送sql接口
		ResultSet result = null;//结果集接口
		
		try {
			Class.forName("com.mysql.jdbc.Driver");
			String url = "jdbc:mysql://127.0.0.1:3306/test02";
			String username = "root";
			String password = "root";
			connection = DriverManager.getConnection(url,username,password);
			statement = (Statement) connection.createStatement();
			result = statement.executeQuery("select * from tb_customer_info");
			while (result.next()) {//下一行数据
				int id = result.getInt("id");
				String name = result.getString(2);
				String sex = result.getString("sex");
				System.out.println("id: "+id+" name: "+name+" sex: "+sex);
			}
			
		} catch (ClassNotFoundException | SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally {



//关闭和创建的顺序相反
			if (result!=null) {
				try {
					result.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(connection!=null){
				try {
					connection.close();
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			
		}
	}
}