Update Batch.php

Author: mavinoo

src/Batch.php

@@ -72,7 +72,7 @@ public function update(Model $table, array $values, string $index = null, bool $
  if ($field !== $index) {
  $finalField = $raw ? Common::mysql_escape($val[$field]) : "'" . Common::mysql_escape($val[$field]) . "'";
  $value = (is_null($val[$field]) ? 'NULL' : $finalField);
- $final[$field][] = 'WHEN "' . $index . '" = \'' . $val[$index] . '\' THEN ' . $value . ' ';
+ $final[$field][] = 'WHEN `' . $index . '` = \'' . $val[$index] . '\' THEN ' . $value . ' ';
  }
  }
  }