Table: south_korea_davis_cup
Columns: player
years_played
total_w_l
singles_w_l
doubles_w_l

Question: what's the years played with singles w-l of 3–2
SQL: SELECT "years_played" FROM south_korea_davis_cup WHERE "singles_w_l" = '3–2'

Question: what's the doubles w-l for player seol jae-min (none)
SQL: SELECT "doubles_w_l" FROM south_korea_davis_cup WHERE "player" = 'Seol Jae-Min (none)'

Question: what's the singles w-l for kim doo-hwan
SQL: SELECT "singles_w_l" FROM south_korea_davis_cup WHERE "player" = 'Kim Doo-Hwan'

Question: what's the total number of singles w-l with doubles w-l of 0–0 and total w-l of 3–1
SQL: SELECT COUNT("singles_w_l") FROM south_korea_davis_cup WHERE "doubles_w_l" = '0–0' AND "total_w_l" = '3–1'

Question: what's the doubles w-l with years played value of 1 (1968)
SQL: SELECT "doubles_w_l" FROM south_korea_davis_cup WHERE "years_played" = '1 (1968)'

Question: what years are played for player  im chung-yang
SQL: SELECT "years_played" FROM south_korea_davis_cup WHERE "player" = 'Im Chung-Yang'