首页 > IT职业 > IT职场 > 浅析SQL语句行列转换的两种方法
CREATE DATABASE tmp
go
USE tmp
go
CREATE TABLE [Scores]
(
[ID] INT IDENTITY(1, 1)
PRIMARY KEY ,
[Student] VARCHAR(20) ,
[Subject] VARCHAR(30) ,
[Score] FLOAT
)
go
TRUNCATE TABLE Scores
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' )
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
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
来自 “ ITPUB博客 ” ,链接:https://blog.itpub.net/406/viewspace-2810548/ ,如需转载,请注明出处,否则将追究法律责任。