What documents types have more than 2 corresponding documents?
select document_type_code from documents group by document_type_code having count ( * ) > 2
What is the document type for document name Learning English?
select document_type_code from documents where document_name = "Learning English"
What documents types have more than 2 corresponding documents?
select document_type_code from documents group by document_type_code having count ( * ) > 2
List all the document name?
select document_name from documents