Get previous page ID

Gets the ID of the previous page, but the result of the output is false,
Asking for advice

Reply to discussion (solution)

Do you have the previous page to pass the post value, the URL is passed to the current PHP file?

Var_dump ($_post);
Look, hope the answer is helpful to you.

I find it strange that the page actually has an ID??

Output false
Are you Var_dump ($result); query no data?

This is the value of the previous page

There should be no mistakes in other aspects

Do you have a value for the $resurt[' ID ' of the previous page output, or are you sure the URL is passed correctly?

You're sure it's $_post[file_id], not $_post[' file_id ';

file_id shown in #5 is a URL variable
You use $_post[' file_id '] of course you don't get a value.
To use $_get[' file_id ').

$field = $_get[' field '];

Use a hyper-connected transfer that belongs to get mode, using $_get.

Thanks, I've solved it.

