Table: us_congress_states
Columns: state_class
vacator
reason_for_change
successor
date_of_successors_formal_installation

Question: What is the number of vacators when the successor was William H. Wells ( F )?
SQL: SELECT COUNT("vacator") FROM us_congress_states WHERE "successor" = 'William H. Wells ( F )'

Question: What is the total number of dates of successor formal installation when the vacator was Joshua Clayton ( F )?
SQL: SELECT COUNT("date_of_successors_formal_installation") FROM us_congress_states WHERE "vacator" = 'Joshua Clayton ( F )'

Question: What is the total number of successors when the vacator was William North ( F )
SQL: SELECT COUNT("successor") FROM us_congress_states WHERE "vacator" = 'William North ( F )'

Question: What are all the states (class) when the successor was Joseph Anderson ( DR )?
SQL: SELECT "state_class" FROM us_congress_states WHERE "successor" = 'Joseph Anderson ( DR )'

Question: What are all the states (class) when the reason for change was resigned November 26, 1798 and the vacator was John Hunter ( DR )?
SQL: SELECT "state_class" FROM us_congress_states WHERE "reason_for_change" = 'Resigned November 26, 1798' AND "vacator" = 'John Hunter ( DR )'