php - 检查数据库表的滚动计数是否已更改

Question

我正在尝试检查MySQL数据库中表的行数是否已更改。代码我检查了数据库但没有存储先前计数的记录，所以我可以比较两者。

function showapp_count(){

global $wpdb;

$lastappcount = '';

$app_count = $wpdb->get_var("SELECT COUNT(*) FROM cb_apps" );

if($app_count !== $lastappcount) {

    $lastappcount = $app_count;

    echo $echoed = $app_count;

    } else{

        echo 'roll count has changed';
    }

}

Answer 1

试试这个解决方案。

function showapp_count(){

  global $wpdb;

  if (isset($_SESSION['last_count'])) {
    $lastappcount = $_SESSION['last_count'];
  } else {
    session_start();
    $_SESSION['last_count'] = 0;
  }

  $app_count = $wpdb->get_var("SELECT COUNT(*) FROM cb_apps" );

  if($app_count !== $lastappcount) {
     $_SESSION['last_count'] = $app_count;
     echo 'Current count is '.$_SESSION['last_count'];
   } else{
     echo "roll count hasn't changed";
   }
}