摘要: 1. WHERE 搜索条件在进行分组操作之前应用;而 HAVING 搜索条件在进行分组操作之后应用。 SELECT Customer,SUM(OrderPrice) FROM Orders WHERE Customer='Bush' OR Customer='Adams' GROUP BY Cust 阅读全文
posted @ 2021-12-01 15:34 dsfsadfdgd 阅读(27) 评论(0) 推荐(0) 编辑