1 题目
这确实是一个真实的面试题，琢磨一下吧！知识不用，就会丢掉，我太依赖各种框架和dll了，已经忘记了最基本的东西。有多久没有写过SQL了，我已经不记得了。
已知表信息如下：
Department(depID, depName),depID 系编号，DepName系名
Student(stuID, name, depID) 学生编号，姓名，系编号
Score(stuID, category, score) 学生编码，科目，成绩
找出每一个系的最高分，并且按系编号，学生编号升序排列，要求顺序输出以下信息：
系编号，系名，学生编号，姓名，总分
2 实验
USE [test] GO /****** Object: Table [dbo].[Score] Script Date: 05/11/2015 23:16:23 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[Score]( [stuID] [int] NOT NULL, [category] [varchar](50) NOT NULL, [score] [int] NOT NULL ) ON [PRIMARY] GO SET ANSI_PADDING OFF GO INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (1, N'英语', 80) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (2, N'数学', 80) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (1, N'数学', 70) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (2, N'英语', 89) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (3, N'英语', 81) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (3, N'数学', 71) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (4, N'数学', 91) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (4, N'英语', 61) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (5, N'英语', 91) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (6, N'英语', 89) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (7, N'英语', 77) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (8, N'英语', 97) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (9, N'英语', 57) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (5, N'数学', 87) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (6, N'数学', 89) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (7, N'数学', 80) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (8, N'数学', 81) INSERT [dbo].[Score] ([stuID], [category], [score]) VALUES (9, N'数学', 84) /****** Object: Table [dbo].[Department] Script Date: 05/11/2015 23:16:23 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[Department]( [depID] [int] IDENTITY(1,1) NOT NULL, [depName] [varchar](50) NOT NULL, PRIMARY KEY CLUSTERED ( [depID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO SET ANSI_PADDING OFF GO SET IDENTITY_INSERT [dbo].[Department] ON INSERT [dbo].[Department] ([depID], [depName]) VALUES (1, N'计算机') INSERT [dbo].[Department] ([depID], [depName]) VALUES (2, N'生物') INSERT [dbo].[Department] ([depID], [depName]) VALUES (3, N'数学') SET IDENTITY_INSERT [dbo].[Department] OFF /****** Object: Table [dbo].[Student] Script Date: 05/11/2015 23:16:23 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[Student]( [stuID] [int] IDENTITY(1,1) NOT NULL, [stuName] [varchar](50) NOT NULL, [deptID] [int] NOT NULL, PRIMARY KEY CLUSTERED ( [stuID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO SET ANSI_PADDING OFF GO SET IDENTITY_INSERT [dbo].[Student] ON INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (1, N'计算机张三', 1) INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (2, N'计算机李四', 1) INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (3, N'计算机王五', 1) INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (4, N'生物amy', 2) INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (5, N'生物kity', 2) INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (6, N'生物lucky', 2) INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (7, N'数学_yiming', 3) INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (8, N'数学_haoxue', 3) INSERT [dbo].[Student] ([stuID], [stuName], [deptID]) VALUES (9, N'数学_wuyong', 3) SET IDENTITY_INSERT [dbo].[Student] OFF /****** Object: Default [DF__Departmen__depNa__5441852A] Script Date: 05/11/2015 23:16:23 ******/ ALTER TABLE [dbo].[Department] ADD DEFAULT ('') FOR [depName] GO /****** Object: Default [DF__Score__category__5EBF139D] Script Date: 05/11/2015 23:16:23 ******/ ALTER TABLE [dbo].[Score] ADD DEFAULT ('') FOR [category] GO /****** Object: Default [DF__Score__score__5FB337D6] Script Date: 05/11/2015 23:16:23 ******/ ALTER TABLE [dbo].[Score] ADD DEFAULT ((0)) FOR [score] GO /****** Object: Default [DF__Student__stuName__59063A47] Script Date: 05/11/2015 23:16:23 ******/ ALTER TABLE [dbo].[Student] ADD DEFAULT ('') FOR [stuName] GO /****** Object: ForeignKey [FK__Student__deptID__59FA5E80] Script Date: 05/11/2015 23:16:23 ******/ ALTER TABLE [dbo].[Student] WITH CHECK ADD FOREIGN KEY([deptID]) REFERENCES [dbo].[Department] ([depID]) GO |
准备环境
3 结果
面试的时候，没有写出来，当时脑袋昏沉沉的。也确实好久没有写复杂的sql语句了。今天花了2到3个小时，终于试出来了。不知道有没有更好的写法？
-- 每个系里的最高分的学生信息
SELECT Department.depID, Department.depName, Student.stuID, stuName, Dscore.scores FROM Department LEFT JOIN Student on department.depID = student.deptID LEFT JOIN (SELECT Score.stuId, SUM(Score) AS scores FROM Score GROUP by stuID ) AS Dscore on Student.stuID = dScore.stuID where exists ( select * from ( SELECT deptID, MAX(scores) AS topScores FROM Student LEFT JOIN ( SELECT stuID,SUM(score) AS scores FROM Score GROUP BY stuID) AS newScore ON Student.stuID = newScore.stuID group by deptID) AS depScore where Department.depID = depScore.deptID and Dscore.scores=depScore.topScores ) order by Department.depID,Student.stuID; |
