Table: election_results_1989
Columns: constituency
winner
party
margin
runner_up_a
party_a

Question: How many margins have a winner of S. Singaravadivel?
SQL: SELECT COUNT("margin") FROM election_results_1989 WHERE "winner" = 'S. Singaravadivel'

Question: How many winners have a runner-up of A. Karthikeyan?
SQL: SELECT COUNT("winner") FROM election_results_1989 WHERE "runner_up_a" = 'A. Karthikeyan'

Question: What is every party with a winner of P. Chidambaram?
SQL: SELECT "party_a" FROM election_results_1989 WHERE "winner" = 'P. Chidambaram'

Question: What is every party A with a constituency of Tiruchendur?
SQL: SELECT "party_a" FROM election_results_1989 WHERE "constituency" = 'Tiruchendur'