给列或表别名
列的 SQL 别名语法
SELECT column_name AS alias_name
FROM table_name;
表的 SQL 别名语法
SELECT column_name(s)
FROM table_name AS alias_name;
实例:
SELECT name, CONCAT(url, ', ', alexa, ', ', country) AS site_info
FROM Websites;
SELECT w.name, w.url, a.count, a.date
FROM Websites AS w, access_log AS a
WHERE a.site_id=w.id and w.name="菜鸟教程";