What are the dates for the documents with both 'GV' type and 'SF' type expenses?
create table documents_with_expenses (document_id varchar, budget_type_code varchar, PRIMARY KEY (document_id)); create table documents (document_date varchar, document_id varchar, PRIMARY KEY (document_date))
select t1.document_date from documents as t1 join documents_with_expenses as t2 on t1.document_id = t2.document_id where t2.budget_type_code = 'gv' intersect select t1.document_date from documents as t1 join documents_with_expenses as t2 on t1.document_id = t2.document_id where t2.budget_type_code = 'sf'