[大数据]java增删改

java增删改实现

//1.获取连接对象
Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "123456");
//2. 准备数据库
      sql = "insert into test1.hero values(null,'jj','男',25)";
sql = "insert into test1.hero values(null,'jj','男',25)";
//3. 创建一个sql对象
        Statement statement = connection.createStatement();     //4.发送sql给mysql服务器执行
      int i = statement.executeUpdate(sql);
      //5.处理结果
        System.out.println(i);
 //6.释放资源
        statement.close();
        connection.close();

两种简化方式

抽取

public class Hello02 {
    private Connection connection;
    private String sql;
    @Before
    public void init() throws SQLException {
        connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test1", "root", "123456");
    }

    @Test
    public void testAdd() throws SQLException {
               //2. 准备数据库
      sql = "insert into test1.hero values(null,'jj','男',25)";
    }
@Test
    public void testUpdate() throws Exception {
        //2. 准备数据库
     sql = "update hero set age=age+1 where name='jj'";

}
    @Test
    public void testDelete () throws SQLException {
        //2. 准备数据库
        sql = "delete from hero where name='jj'";
        
    }
    @After
    public void Destory() throws SQLException {
        //3. 创建一个sql对象
        Statement statement = connection.createStatement();
      //4.发送sql给mysql服务器执行
        int i = statement.executeUpdate(sql);
        //5.处理结果
        System.out.println(i);
        

        
        //6.释放资源
        statement.close();
        connection.close();
    }
}

封装

public class jdbcUtils {
    public static void main(String[] args) throws SQLException {
        //update("insert into test1.hero values(null,'jj','男',25)");
        update("update hero set age=age+1 where name='jj'");
    }
public static void update(String sql) throws SQLException {
        //1. 获取连接对象
        Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test1", "root", "123456");
        //3. 创建一个sql对象
        Statement statement = connection.createStatement();
        //4.发送sql给mysql服务器执行
        int i = statement.executeUpdate(sql);
        //5.处理结果
        System.out.println(i);
        //6.释放资源
        statement.close();
        connection.close();
    }

}