Club Drupal

  /**

   * The database connection.

   *

   * @var DatabaseConnection

   */

    return $this->connection->query("SELECT table_name AS table_name FROM information_schema.tables WHERE " . (string) $condition, $condition->arguments())->fetchAllKeyed(0, 0);

  }

  /**

   * Finds all tables that are like the specified base table name. This is a

   * backport of the change made to findTables in Drupal 8 to work with virtual,

   * un-prefixed table names. The original function is retained for Backwards

   * Compatibility.

   * @see https://www.drupal.org/node/2552435

   *

   * @param string $table_expression

   *   An SQL expression, for example "cache_%" (without the quotes).

   *

   * @return array

   *   Both the keys and the values are the matching tables.

   */

  public function findTablesD8($table_expression) {

    // Load all the tables up front in order to take into account per-table

    // prefixes. The actual matching is done at the bottom of the method.

    $condition = $this->buildTableNameCondition('%', 'LIKE');

    $condition->compile($this->connection, $this);

    $individually_prefixed_tables = $this->connection->getUnprefixedTablesMap();

    $default_prefix = $this->connection->tablePrefix();

    $default_prefix_length = strlen($default_prefix);

    $tables = array();

    // Normally, we would heartily discourage the use of string

    // concatenation for conditionals like this however, we

    // couldn't use db_select() here because it would prefix

    // information_schema.tables and the query would fail.

    // Don't use {} around information_schema.tables table.

    $results = $this->connection->query("SELECT table_name AS table_name FROM information_schema.tables WHERE " . (string) $condition, $condition->arguments());

    foreach ($results as $table) {

      // Take into account tables that have an individual prefix.

      if (isset($individually_prefixed_tables[$table->table_name])) {

        $prefix_length = strlen($this->connection->tablePrefix($individually_prefixed_tables[$table->table_name]));

      }

      elseif ($default_prefix && substr($table->table_name, 0, $default_prefix_length) !== $default_prefix) {

        // This table name does not start the default prefix, which means that

        // it is not managed by Drupal so it should be excluded from the result.

        continue;

      }

      else {

        $prefix_length = $default_prefix_length;

      }

      // Remove the prefix from the returned tables.

      $unprefixed_table_name = substr($table->table_name, $prefix_length);

      // The pattern can match a table which is the same as the prefix. That

      // will become an empty string when we remove the prefix, which will

      // probably surprise the caller, besides not being a prefixed table. So

      // remove it.

      if (!empty($unprefixed_table_name)) {

        $tables[$unprefixed_table_name] = $unprefixed_table_name;

      }

    }

    // Convert the table expression from its SQL LIKE syntax to a regular

    // expression and escape the delimiter that will be used for matching.

    $table_expression = str_replace(array('%', '_'), array('.*?', '.'), preg_quote($table_expression, '/'));

    $tables = preg_grep('/^' . $table_expression . '$/i', $tables);

    return $tables;