Table: sports_stlouis
Columns: team
sport
league
established
began_in_st_louis
venue
championships_in_st_louis
left_st_louis

Question: What year did Negro American League join?
SQL: SELECT MIN("began_in_st_louis") FROM sports_stlouis WHERE "league" = 'Negro American League'

Question: What year did the team who played at the Scottrade Center leave the city?
SQL: SELECT MIN("left_st_louis") FROM sports_stlouis WHERE "venue" = 'Scottrade Center'

Question: How may championships were won by the team that started in 1950?
SQL: SELECT "championships_in_st_louis" FROM sports_stlouis WHERE "began_in_st_louis" = 1950

Question: How many championships were won for arena football?
SQL: SELECT "championships_in_st_louis" FROM sports_stlouis WHERE "sport" = 'Arena Football'