我试图将文件字段从一个节点复制到另一个节点，当我谷歌如何做到这一点时，我发现了这个解决方案
$fid=9;//fid of the file
$file = file_load($fid);
$node->field_pro_thumbnail[LANGUAGE_NONE][] = array($file);
node_save($node);
但是我得到以下错误
PDOException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'fid' cannot be null: INSERT INTO {file_usage} (fid, module, type, id, count) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4); Array ( [:db_insert_placeholder_0] => [:db_insert_placeholder_1] => file [:db_insert_placeholder_2] => node [:db_insert_placeholder_3] => 51 [:db_insert_placeholder_4] => 1 ) in file_usage_add() (line 692 of C:'xampp'htdocs'someueue'includes'file.inc)."
请帮忙??
可能是这样的:
$node->field_pro_thumbnail[LANGUAGE_NONE][$fid] = array($file);