如何选择特定列的最后一个插入值

 # 连接数据库

 cnx = mysql.connector.connect(user='username', password='password',

                               host='host', database='database_name')

 # 创建游标

 cursor = cnx.cursor()

 # 执行SQL查询语句

 query = "SELECT column_name FROM table_name ORDER BY 插入时间列 DESC LIMIT 1;"

 cursor.execute(query)

 # 获取结果

 result = cursor.fetchone()[0]

 # 关闭游标和数据库连接

 cursor.close()

 cnx.close()

 # 输出结果

 print(result)

 ```

 public class Main {

     public static void main(String[] args) {

         Connection conn = null;

         Statement stmt = null;

         ResultSet rs = null;

         try {

             // 连接数据库

             conn = DriverManager.getConnection("jdbc:mysql://host/database_name", "username", "password");

             // 创建Statement对象

             stmt = conn.createStatement();

             // 执行SQL查询语句

             String query = "SELECT column_name FROM table_name ORDER BY 插入时间列 DESC LIMIT 1;";

             rs = stmt.executeQuery(query);

             // 获取结果

             if (rs.next()) {

                 String result = rs.getString("column_name");

                 System.out.println(result);

             }

         } catch (SQLException e) {

             e.printStackTrace();

         } finally {

             // 关闭ResultSet、Statement和Connection

             try {

                 if (rs != null) {

                     rs.close();

                 }

                 if (stmt != null) {

                     stmt.close();

                 }

                 if (conn != null) {

                     conn.close();

                 }

             } catch (SQLException e) {

                 e.printStackTrace();

             }

         }

     }

 }

 ```

 $dsn = "mysql:host=$host;dbname=$db;charset=$charset";

 $options = [

     PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,

     PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,

     PDO::ATTR_EMULATE_PREPARES   => false,

 ];

 try {

     // 创建PDO对象

     $pdo = new PDO($dsn, $user, $pass, $options);

     // 执行SQL查询语句

     $query = "SELECT column_name FROM table_name ORDER BY 插入时间列 DESC LIMIT 1;";

     $stmt = $pdo->query($query);

     // 获取结果

     $result = $stmt->fetchColumn();

     // 输出结果

     echo $result;

 } catch (\PDOException $e) {

     throw new \PDOException($e->getMessage(), (int)$e->getCode());

 }

 ?>

 ```