UC知道各位高人请帮我看看
来源：百度知道 编辑：UC知道 时间：2024/05/18 04:10:27
学ASP的时候看到这么一段代码:
sqlPic="select top " & ArticleNum
sqlPic=sqlPic & " A.ArticleID,A.ClassID,L.LayoutID,L.LayoutFileName,A.Title,A.Key,A.Author,A.CopyFrom,A.UpdateTime,A.Editor,A.TitleFontColor,A.TitleFontType,"
sqlPic=sqlPic & " A.Hits,A.OnTop,A.Hot,A.Elite,A.Passed,A.IncludePic,A.Stars,A.PaginationType,A.ReadLevel,A.ReadPoint,A.DefaultPicUrl from Article A"
sqlPic=sqlPic & " inner join Layout L on A.LayoutID=L.LayoutID where A.Deleted=0 and A.Passed=1 and DefaultPicUrl<>''"
其中的A.Hits,A.OnTop,A.Hot,A.Elite,A.Passed,A.IncludePic,A.Stars,A.PaginationType,A.ReadLevel,A.ReadPoint,A.DefaultPicUrl每个字段前面都带个A.是什么意思?还有from Article A,我想数据库里面的表应该是Article,可是Article A是什么意思?
sqlPic="select top " & ArticleNum
sqlPic=sqlPic & " A.ArticleID,A.ClassID,L.LayoutID,L.LayoutFileName,A.Title,A.Key,A.Author,A.CopyFrom,A.UpdateTime,A.Editor,A.TitleFontColor,A.TitleFontType,"
sqlPic=sqlPic & " A.Hits,A.OnTop,A.Hot,A.Elite,A.Passed,A.IncludePic,A.Stars,A.PaginationType,A.ReadLevel,A.ReadPoint,A.DefaultPicUrl from Article A"
sqlPic=sqlPic & " inner join Layout L on A.LayoutID=L.LayoutID where A.Deleted=0 and A.Passed=1 and DefaultPicUrl<>''"
其中的A.Hits,A.OnTop,A.Hot,A.Elite,A.Passed,A.IncludePic,A.Stars,A.PaginationType,A.ReadLevel,A.ReadPoint,A.DefaultPicUrl每个字段前面都带个A.是什么意思?还有from Article A,我想数据库里面的表应该是Article,可是Article A是什么意思?
from Article A 他的意思是给Article这个表取个别名A,这样的话在多个表组合查询的时候，容易分辨是那个表的字段
A.Hits = Article.Hits
这里的A就是Article ，可以理解成Article 表的小名（呵呵）