How many events has "Nanjing ( Jiangsu )" hosted?
select count(*) from city as t1 join hosting_city as t2 on t1.city_id = t2.host_city where city = "Nanjing ( jiangsu )"
What is the date of the competition "1994 FIFA World Cup qualification" hosted by "Nanjing ( Jiangsu )"?
select t3.date from city as t1 join hosting_city as t2 on t1.city_id = t2.host_city join match as t3 on t2.match_id = t3.match_id where t1.city = "Nanjing ( jiangsu )" and t3.competition = "1994 fifa world cup qualification"
How about the venue?
select t3.venue from city as t1 join hosting_city as t2 on t1.city_id = t2.host_city join match as t3 on t2.match_id = t3.match_id where t1.city = "Nanjing ( jiangsu )" and t3.competition = "1994 fifa world cup qualification"