java基础之JDBC二：基础应用

Posted 2020-11-17 剑来

JDBC的基础应用CURD：

增删改

public void noQuery() {
    Connection conn = null;
    Statement stat = null;
    try {
        //注册驱动
        Class.forName("com.mysql.jdbc.Driver");
        //获取连接对象
        conn = DriverManager.getConnection("jdbc:mysql:///tempDb", "root", "123");
        stat = conn.createStatement();
        String sql = "---";
　　　　//执行
       int num = stat.executeUpdate(sql);
        if(num > 0) {
            System.out.println("操作成功");
        } else {
            System.out.println("操作失败");
        }
        //释放资源
        stat.close();
        conn.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

 

查询

public static void query() {
    Connection conn = null;
    Statement stat = null;
    try {
        //注册驱动
        Class.forName("com.mysql.jdbc.Driver");
        //获取连接对象
        conn = DriverManager.getConnection("jdbc:mysql:///tempDb", "root", "123");
        stat = conn.createStatement();
        String sql = "select * from users";
        //执行
        ResultSet rs = stat.executeQuery(sql);
        while (rs.next()) {
            int id = rs.getInt("uid");
            String name = rs.getString("uname");
            String psw = rs.getString("psw");
            System.out.println(id + "--" + name + "--" + psw);
        }
        //释放资源
        rs.close();
        stat.close();
        conn.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}