摘要: 1.sql语句执行顺序这也解释了为什么会报mainid找不到,因为这个时候还没执行as这句。2.A confusing aspect of queries containing an OUTER JOIN clause is whether to specify a logical expression in the ON filter or in the WHERE filter.The mai... 阅读全文
posted @ 2010-11-05 17:55 lightwalker 阅读(355) 评论(0) 推荐(0) 编辑