Table: tennis_match_results_26
Columns: outcome
date
surface
partner
opponents
score

Question: What was the partner of the team that faced the guillermo garcía-lópez albert portas on clay?
SQL: SELECT "partner" FROM tennis_match_results_26 WHERE "surface" = 'clay' AND "opponents" = 'guillermo garcía-lópez albert portas'

Question: What are the dates where the opponent was guillermo garcía-lópez albert portas?
SQL: SELECT "date" FROM tennis_match_results_26 WHERE "opponents" = 'guillermo garcía-lópez albert portas'