Table: qinhuangdao_city
Columns: name
hanzi
hanyu_pinyin
population_2004_est
area_km
density_km

Question: What is the 2004 population for 昌黎县?
SQL: SELECT "population_2004_est" FROM qinhuangdao_city WHERE "hanzi" = '昌黎县'

Question: What is the 2004 population for 山海关区?
SQL: SELECT "population_2004_est" FROM qinhuangdao_city WHERE "hanzi" = '山海关区'

Question: Which Hanzi has a suburban population in 2004?
SQL: SELECT "hanzi" FROM qinhuangdao_city WHERE "population_2004_est" = 'suburban'

Question: What is the density of 昌黎县?
SQL: SELECT "density_km" FROM qinhuangdao_city WHERE "hanzi" = '昌黎县'

Question: Which Hanyu Pinyin is labeled rural?
SQL: SELECT "hanyu_pinyin" FROM qinhuangdao_city WHERE "name" = 'rural'