本文实例讲述了MySQL Union合并查询数据及表别名、字段别名用法。分享给大家供大家参考，具体如下：
union关键字
SELECT s_id, f_name, f_price
FROM fruits
WHERE f_price < 9.0
UNION ALL
SELECT s_id, f_name, f_price
FROM fruits
WHERE s_id IN(101,103);
为表取别名
SELECT * from orders AS o
WHERE o.o_num = 30001;
SELECT c.c_id, o.o_num
FROM customers AS c
