CREATE TABLE table_name_21 (name VARCHAR, floors VARCHAR, location VARCHAR, year_proposed VARCHAR)

What building is in ljubljana, proposed in 2010, and has 15 floors?
SELECT name FROM table_name_21 WHERE location = "ljubljana" AND year_proposed = "2010" AND floors = "15"
SELECT "name" FROM "table_name_21" WHERE "15" = "floors" AND "2010" = "year_proposed" AND "ljubljana" = "location"