摘要:
-- 查询5大洲国家总数 SELECT continent,COUNT(*) FROM country GROUP BY continent; -- 演示临时表 CREATE TEMPORARY TABLE tmp_table ( continent VARCHAR(20), COUNT INT ) 阅读全文
摘要:
USE world; -- 查询国家名-首都名列表 SELECT country.name AS '国家名字',city.Name AS '首都名字' FROM country,city WHERE country.capital = city.id; -- 创建视图 语法: -- create v 阅读全文