Table: rookies_game_stats
Columns: game
date
team
score
high_points
high_rebounds
high_assists
location_attendance
record

Question: How many different items appear in the high points column when the location attendance was US Airways Center 18,422?
SQL: SELECT COUNT("high_points") FROM rookies_game_stats WHERE "location_attendance" = 'US Airways Center 18,422'

Question: What was the high assists on April 7?
SQL: SELECT "high_assists" FROM rookies_game_stats WHERE "date" = 'April 7'