How can we query contentdocument which is inserted by community user only?

Hi,

There is no default sharing for an organization, so you have to add a record for it. If you wanted to share everything, you'd add a ContentDocumentLink record for the Org ID. Here is example code of doing that for all ContentDocuments:

Id orgId = UserInfo.getOrganizationId();

List<ContentDocumentLink> existingCDL =
[SELECT Id, LinkedEntityId, ContentDocumentId, ShareType, Visibility
FROM ContentDocumentLink Where LinkedEntityId = :orgId];

Set<Id> alreadyLinked = new Set<Id>();
for(ContentDocumentLink cd : existingCDL)
alreadyLinked.add(cd.ContentDocumentId);

List<ContentDocumentLink> cdl = new List<ContentDocumentLink>();
for(ContentDocument cd : [Select Id From ContentDocument])
{
if(! alreadyLinked.contains(cd.Id))
cdl.add(new ContentDocumentLink(
LinkedEntityId = UserInfo.getOrganizationId(),
ContentDocumentId=cd.Id,
ShareType = 'C',
Visibility = 'AllUsers'));
}
insert cdl;

Hope it will help:

Thanks