Table: simon_greul_match
Columns: date
tournament
surface
opponent
score

Question: What was the surface for Adrian Ungur as an opponent?
SQL: SELECT "surface" FROM simon_greul_match WHERE "opponent" = 'adrian ungur'

Question: What was the score on a clay surface on May 29, 2006?
SQL: SELECT "score" FROM simon_greul_match WHERE "surface" = 'clay' AND "date" = 'may 29, 2006'

Question: Which tournament had a score of 6–3, 7–6?
SQL: SELECT "tournament" FROM simon_greul_match WHERE "score" = '6–3, 7–6'

Question: On what surface was the opponent Michael Berrer?
SQL: SELECT "surface" FROM simon_greul_match WHERE "opponent" = 'michael berrer'