<?php

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

$host = 'localhost';
$dbuser = 'root';
$dbpass = 'root';
$db = 'drupal7_4';

$con = mysqli_connect($host, $dbuser, $dbpass, $db);
$result = array_column(mysqli_fetch_all($con->query('SHOW TABLES')), 0);
foreach ($result as $key => $table_name) {

  if (ignore_table($table_name)) {
    $mysqli = new mysqli($host, $dbuser, $dbpass, $db);
    $create_trigger_sql = "
                    CREATE TRIGGER avoide_delete_" . $table_name . "
                    BEFORE DELETE
                    ON " . $table_name . "
                    FOR EACH ROW
                    BEGIN
                        CALL cannot_delete_error;
                    END;
                    ";
    $drop_trigger_sql = "DROP TRIGGER IF EXISTS avoide_delete_" . $table_name;
    $mysqli->query($drop_trigger_sql);
    $mysqli->query($create_trigger_sql);
    var_dump($con->error);
    $status[] = "Created Trigger is : avoide_delete_" . $table_name;
    mysqli_close($mysqli);
  }
}
mysqli_close($con);

echo '<pre>';
print_r($status);
echo '</pre>';

function ignore_table($table_name) {
  $tables = array('semaphore', 'sessions', 'watchdog');

  if (in_array($table_name, $tables)) {
    return FALSE;
  }

  $name = explode('_', $table_name);
  if ($name[0] == 'cache') {
    return FALSE;
  }

  return TRUE;
}

?>