Table: election_results_1930_2
Columns: district
incumbent
party
first_elected
result
candidates

Question: what's the district with incumbent being richard j. welch
SQL: SELECT "district" FROM election_results_1930_2 WHERE "incumbent" = 'Richard J. Welch'

Question: what's the districtwith party being democratic
SQL: SELECT "district" FROM election_results_1930_2 WHERE "party" = 'Democratic'

Question: what's the district with candidates being harry lane englebright (r) unopposed
SQL: SELECT "district" FROM election_results_1930_2 WHERE "candidates" = 'Harry Lane Englebright (R) Unopposed'

Question:  how many candidates with district being california 7
SQL: SELECT COUNT("candidates") FROM election_results_1930_2 WHERE "district" = 'California 7'

Question: what's the party with incumbent being william e. evans
SQL: SELECT "party" FROM election_results_1930_2 WHERE "incumbent" = 'William E. Evans'