Day1_1--通过jdbc驱动程序连接mysql数据库+测试（hamcrest+junit）

1. idea项目导入mysql对应版本jar包驱动
   File->Project Structure->Libraries
   点击加号添加驱动并Apply
2. 参考代码

import org.junit.Test;
import java.sql.*;

/**
* @author nanzhi
* @date 2024/7/15 9:52
*/
public class k1_jdbc {
   public static void main(String[] args) {
       try {
//            1.加载驱动
           Class.forName("com.mysql.cj.jdbc.Driver");
//            2.创建链接
           String url = "jdbc:mysql://localhost:3306/zy45";
           String user = "root";
           String pw = "123456";
           Connection conn = DriverManager.getConnection(url, user, pw);
//            3.创建语句
           Statement stmt = conn.createStatement();
//            4.执行语句
           String sql = "select * from students";
           ResultSet rs = stmt.executeQuery(sql);
//            5.处理结果
           while (rs.next()) {
               System.out.println(rs.getString("sno"));
           }
//            6.关闭对象
           rs.close();
           stmt.close();
           conn.close();
       } catch (Exception e) {
           e.printStackTrace();
       }
   }

   /**
    * 正式环境进行crud操作通过实例化对象调用对应方法
    * 测试时：通过导入hamcrest和junit两个jar包可以实现
    * 给需要执行测试的方法前加上@Test注解直接运行该方法的代码
    */
   public static void main1(String[] args) throws ClassNotFoundException, SQLException {
       k1_jdbc k1_jdbc = new k1_jdbc();
       k1_jdbc.insert();
   }

   @Test
   public void insert() throws SQLException, ClassNotFoundException {
       //1.加载驱动
       Class.forName("com.mysql.cj.jdbc.Driver");

       //2.获取链接
       Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/zy45?useSSL=false&serverTimezone=UTC",
               "root",
               "123456");
       //3.定义sql

       //String sql="insert into students values(188,'李同学','女','2004-02-02','8899')";
       String sql = "delete from students where sno=188";

       //4.创建数据操作对象
       Statement statement = connection.createStatement();

       //5.执行sql，获取结果集
       int i = statement.executeUpdate(sql);
       System.out.println("向数据库中插入/删除了i = " + i);

       //6. 关闭资源
       //关闭资源
       statement.close();
   }
}