/*创建数据库*/  CREATE DATABASE tmp  go  USE tmp  go /*创建数据库测试表*/ CREATE TABLE [Scores]      (        [ID] INT IDENTITY(1, 1)                 PRIMARY KEY ,        [Student] VARCHAR(20) ,        [Subject] VARCHAR(30) ,        [Score] FLOAT      ) go TRUNCATE TABLE Scores  /*插入数据库测试数据信息*/   INSERT  INTO Scores          ( Student, Subject, Score )  VALUES  ( 'test001', '语文', '90' )  INSERT  INTO Scores          ( Student, Subject, Score )  VALUES  ( 'test001', '英语', '85' )  INSERT  INTO Scores          ( Student, Subject, Score )  VALUES  ( 'text002', '语文', '90' )  INSERT  INTO Scores          ( Student, Subject, Score )  VALUES  ( 'text002', '英语', '80' )  INSERT  INTO Scores          ( Student, Subject, Score )  VALUES  ( 'test003', '语文', '95' )  INSERT  INTO Scores          ( Student, Subject, Score )  VALUES  ( 'test003', '英语', '85' ) /*1.  case when .......then else  ....end 用法，行列转换*/  SELECT  Student AS '姓名' ,          MAX(CASE Subject                WHEN '语文' THEN Score                ELSE 0              END) AS '语文' ,--如果这个行是“语文”，就选此行作为列         MAX(CASE Subject                WHEN '英语' THEN Score                ELSE 0              END) AS '英语' FROM    Scores  GROUP BY Student  ORDER BY Student /*2. pivot(聚合函数(要转成列值的列名) 　      for 要转换的列  　　    in（目标列名）  　　)*/ SELECT  Student AS '姓名' ,          AVG(语文) AS '语文' ,          AVG(英语) AS '英语' FROM    Scores PIVOT( AVG(Score) FOR Subject IN ( 语文, 英语 ) )as NewScores  GROUP BY Student  ORDER BY Student ASC