Table: election_results_2000_4
Columns: district
incumbent
party
first_elected
results
candidates

Question: How many parties is the incumbent Bob Brady a member of?
SQL: SELECT COUNT("party") FROM election_results_2000_4 WHERE "incumbent" = 'Bob Brady'

Question: How many candidates were there in the district won by Joe Hoeffel?
SQL: SELECT COUNT("candidates") FROM election_results_2000_4 WHERE "incumbent" = 'Joe Hoeffel'

Question: Who were the candidates in district Pennsylvania 3?
SQL: SELECT "candidates" FROM election_results_2000_4 WHERE "district" = 'Pennsylvania 3'

Question: What's the first elected year of the district whose incumbent is Jim Greenwood?
SQL: SELECT MAX("first_elected") FROM election_results_2000_4 WHERE "incumbent" = 'Jim Greenwood'