我对sql语句中的优先级操作有疑问。DISTINCT t2.c1) as count_c1 FROM t1 JOIN t2将首先应用此查询中的哪个筛选器正如我所理解的,拥有的条件是最后的,这意味着服务器生成完整的记录集,然后删除所有count_c1 <1的行并将结果返回给客户端。在哪里是第一位的</em
我有orders表,有id,customer_id和amt字段
SELECT customer_id, MAX(amt) FROM orders;SELECT customer_id, MAX(amt) AS maximum FROM orders GROUP BY customer_id ORDER BY maximumDESC LIMIT 1;
得到了