CREATE TABLE table_name_97 (years VARCHAR, jersey_number_s_ VARCHAR, position VARCHAR)

What is Years, when Jersey Number(s) is 21, and when Position is SG?
SELECT years FROM table_name_97 WHERE jersey_number_s_ = "21" AND position = "sg"
SELECT "years" FROM "table_name_97" WHERE "21" = "jersey_number_s_" AND "position" = "sg"