Entity Field Query OR condition,between node title and a custom field
`
function hook_query_customproductstag_alter(QueryAlterableInterface $query) {
  $keys = $query->getMetaData('keys');
  $or = db_or()
    //->fieldCondition('field_usage_number', 'value','%'. $keys .'%', 'LIKE')
    //->propertyCondition('title','%'.$keys .'%', 'LIKE');
    ->condition('usage.field_usage_number_value', '%' . db_like($keys) . '%', 'LIKE')
    ->condition('node.title', '%' . db_like($keys) . '%', 'LIKE');

$query->condition($or);
}  `

fieldCondition didn't work because db_or is not a part of entity query.