Table: redskins_defense_stats_2008
Columns: player
tackles
asst
totaltk
sack
yards
fumr

Question: What is the total of yards when asst. is 19, totaltk is 60 and sack is more than 0?
SQL: SELECT SUM("yards") FROM redskins_defense_stats_2008 WHERE "asst" = 19 AND "totaltk" = 60 AND "sack" > 0

Question: what is the total sack for mike green when fumr is less than 0?
SQL: SELECT SUM("sack") FROM redskins_defense_stats_2008 WHERE "player" = 'mike green' AND "fumr" < 0

Question: what is the total sack when totaltk is 1 and asst. is more than 0?
SQL: SELECT SUM("sack") FROM redskins_defense_stats_2008 WHERE "totaltk" = 1 AND "asst" > 0

Question: what is the total number of tackles when fumr is 0, totaltk is 54 and yards is less than 0?
SQL: SELECT COUNT("tackles") FROM redskins_defense_stats_2008 WHERE "fumr" = 0 AND "totaltk" = 54 AND "yards" < 0

Question: what is the sum of totaltk when yards is less than 0?
SQL: SELECT SUM("totaltk") FROM redskins_defense_stats_2008 WHERE "yards" < 0