Table: africa_swim_2006
Columns: rank
nation
gold
silver
bronze
total

Question: For all countries with 7 bronze medals and a total number of medals less than 13, what's the sum of silver medals?
SQL: SELECT SUM("silver") FROM africa_swim_2006 WHERE "bronze" = 7 AND "total" < 13

Question: For countries with total number of medals less than 5 and more than 2 bronze medals, what's the lowest number of gold medals?
SQL: SELECT MIN("gold") FROM africa_swim_2006 WHERE "total" < 5 AND "bronze" > 2