最近面试遇到了一道面试题,顿时有点迷糊,只说出了思路,后来百度了一下,整理了一下思路,于是记录下来,方便以后学习。(面试题请参见附件) 相关的数据表: 1.Score表 2.[Us
最近面试遇到了一道面试题,顿时有点迷糊,只说出了思路,后来百度了一下,整理了一下思路,于是记录下来,方便以后学习。(面试题请参见附件) 相关的数据表: 1.Score表 2.[User]表 SQL语句如下: --方法一:静态SQL 复制代码 代码如下: SELECT * FROM (SELECT UID,Name, Score,ScoreName FROM Score,[User] WHERE Score.UID=[User].ID) AS SourceTable PIVOT(AVG(Score)FOR ScoreName IN ([英语], [数学])) AS a --方法二:动态SQL 复制代码 代码如下: DECLARE @s NVARCHAR(4000) SELECT @s = ISNULL(@s + ',', '') + QUOTENAME(ScoreName) FROM (select distinct ScoreName from Score) as A ---列名不要重复 Declare @sql NVARCHAR(4000) SET @sql=' select r.* from (select UID,Name,ScoreName,Score from Score,[User] where Score.UID=[User].ID) as t pivot ( max(t.Score) for t.ScoreName in ('+@s+') ) as r' EXEC( @sql) --方法三:Case When 复制代码 代码如下: select row_number() OVER(ORDER BY [User].ID) as 编号, UID as 用户编号, Name as 姓名, max(case ScoreName when '英语' then Score else 0 end) 英语, max(case ScoreName when '数学' then Score else 0 end) 数学 from Score,[User] WHERE Score.UID=[User].ID group by UID,[User].ID,Name