jdbc链接mysql

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

import org.junit.Test;

public class test {
    @Test
    public void testJdbcInsert(){
        PreparedStatement prepareStatement = null;
        Connection connection = null;
        try {
            //1.加载驱动
            Class.forName("com.mysql.jdbc.Driver");
            //2.获得链接
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");
            //3.编写sql语句
            String sql ="insert into product values (null,?,?,?)";
            //4.预编译
            prepareStatement = connection.prepareStatement(sql);
            //5.设置参数
            prepareStatement.setString(1, "苹果");
            prepareStatement.setDouble(2, 3.5);
            prepareStatement.setObject(3, new Date());
            //6.执行
            prepareStatement.executeUpdate();

        } catch (ClassNotFoundException | SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            //7.关闭资
            try {
                if(prepareStatement!=null){
                    prepareStatement.close();
                }
                if(connection!=null){
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }
    @Test
    public void testJdbcSelect(){
        PreparedStatement prepareStatement = null;
        Connection connection = null;
        ResultSet executeQuery = null;
        try {
            //1.加载驱动
            Class.forName("com.mysql.jdbc.Driver");
            //2.获得链接
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");
            //3.编写sql语句
            String sql ="select * from product where pid=?";
            //4.预编译
            prepareStatement = connection.prepareStatement(sql);
            //5.设置参数
            prepareStatement.setInt(1, 1);
            //6.执行
            executeQuery = prepareStatement.executeQuery();

            while(executeQuery.next()){
                System.out.println(executeQuery.getInt(1));
                System.out.println(executeQuery.getString(2));
                System.out.println(executeQuery.getDouble(3));
                System.out.println(executeQuery.getDate(4));
            }
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }finally {
            //7.关闭资
            try {
                if(executeQuery!=null){
                    executeQuery.close();
                }
                if(prepareStatement!=null){
                    prepareStatement.close();
                }
                if(connection!=null){
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }
}

/*
注意jdbc的修改 删除 添加都除了sql语句都差不多，所以这里就只写了一个添加

预编译不仅能提高性能还能防止sql注入
*/