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学生选课系统---数据库课程设计SQL Server

可以直接从我的GitHub中获取文档: 学生选课系统GitHub 一 题目 学生选课系统 二 需求分析 1.根据学生专业学年学期等信息,录入课程完成课程计划2.根据课程计划,录入任课教师信息3.学生可以根据学年学期等信息,选择课程完成选课要求 三 结构概念设计 计划受众表信息学生表信息教师表信息课程表信息教学计划表信息任课表信息学生选课表信息 四 ER图(基于三级范式) 这里我遇到一个问题如何设计ER图 和如何根据ER图设计关系逻辑呢? 数据库设计方法 看了以上这篇 收益很多 可以参考下 五 数据字典 Stdunt表(学生表) 字段名 数据类型 长度 约束 描述 字段名 数据类型 长度 约束 描述 Student_id Nvar char 50 主键 学生学号 Gender Nvarchar 50 无 性别 Name Nvarchar 50 无 学生名字 category Nvarchar 50 无 种类 Course表(课程表) 字段名 数据类型 长度 约束 描述 course_id Nvarchar 50 主键 课程号 Name Nvarchar 50 唯一键 课程名 mode Nvarchar 50 无 考核方式 Credit Int 无 学分 each表(教师任课表) 字段名 数据类型 长度 约束 描述 Teach_id Nvarchar 50 主键 任课号 Plan_id Nvarchar 50 外键,组合唯一键 教学计划号 Teacher_id Nvarchar 50 外键,组合唯一键 教师编号 Teacher表(教师表) 字段名 数据类型 长度 约束 描述 Teacher_id Nvarchar 50 主键 教师编号 Name Nvarchar 50 无 教师名 Gender Nvarchar 50 无 性别 Student_select表(学生选课表) 字段名 数据类型 长度 约束 描述 Select_id Nvarchar 50 主键 选课号 Student_id Nvarchar 50 外键,组合唯一键 学生编号 Teach_id Nvarchar 50 外键,组合唯一键 排课编号 Administrator表 字段名 数据类型 长度 约束 描述 administrator Nvarchar 50 管理员号 password Nvarchar 50 密码 Plan表(教学计划表) 字段名 数据类型 长度 约束 描述 plan_id nvarchar 50 主键 教学计划号 audience_id nvarchar 50 外键,组合唯一键 计划受众号 course_id nvarchar 50 外键,组合唯一键 课程号 audience表(计划受众表) 字段名 数据类型 长度 约束 描述 auience_id nvarchar 50 主键约束 计划受众id academy nvarchar 50 无 学院 major nvarchar 50 无 专业 grade nvarchar 50 无 年级 semester Int 无 学期 六 数据库定义语句 CREATE DATABASE [Student_Select] GO USE [Student_Select] GO /****** Object: Table [dbo].[Teacher] Script Date: 06/27/2018 10:37:01 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Teacher]( [teacher_id] [nvarchar](50) NOT NULL, [name] [nvarchar](50) NULL, [gender] [nchar](10) NULL, CONSTRAINT [PK_Teacher] PRIMARY KEY CLUSTERED ( [teacher_id] 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 INSERT [dbo].[Teacher]([teacher_id], [name], [gender]) VALUES (N'1', N'1', N'1 ') INSERT [dbo].[Teacher]([teacher_id], [name], [gender]) VALUES (N'2', N'2', N'2 ') /****** Object: Table [dbo].[Course] Script Date: 06/27/2018 10:37:01 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Course]( [course_id] [nvarchar](50) NOT NULL, [name] [nvarchar](50) NULL, [mode] [nvarchar](50) NOT NULL, [credit] [nvarchar](50) NULL, CONSTRAINT [PK_Course] PRIMARY KEY CLUSTERED ( [course_id] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY], CONSTRAINT [IX_Course] UNIQUE NONCLUSTERED ( [name] 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 EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'考核方式' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Course', @level2type=N'COLUMN',@level2name=N'mode' GO INSERT [dbo].[Course]([course_id], [name], [mode], [credit]) VALUES (N'1', N'1', N'1', N'1') INSERT [dbo].[Course]([course_id], [name], [mode], [credit]) VALUES (N'2', N'2', N'2', N'2') /****** Object: Table [dbo].[audience] Script Date: 06/27/2018 10:37:01 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[audience]( [audience_id] [nvarchar](50) NOT NULL, [academy] [nvarchar](50) NULL, [major] [nvarchar](50) NULL, [grade] [nvarchar](50) NULL, [semester] [int] NULL, CONSTRAINT [PK_audience] PRIMARY KEY CLUSTERED ( [audience_id] 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 EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'受众ID' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'audience', @level2type=N'COLUMN',@level2name=N'audience_id' GO EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'学院' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'audience', @level2type=N'COLUMN',@level2name=N'academy' GO EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'年级' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'audience', @level2type=N'COLUMN',@level2name=N'grade' GO EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'学期' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'audience', @level2type=N'COLUMN',@level2name=N'semester' GO INSERT [dbo].[audience]([audience_id], [academy], [major], [grade], [semester]) VALUES (N'1', N'1', N'1', N'1', 1) INSERT [dbo].[audience]([audience_id], [academy], [major], [grade], [semester]) VALUES (N'2', N'2', N'2', N'2', 2) /****** Object: Table [dbo].[Administrator] Script Date: 06/27/2018 10:37:01 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Administrator]( [administrator] [nvarchar](50) NULL, [password] [nvarchar](50) NULL ) ON [PRIMARY] GO /****** Object: Table [dbo].[Student] Script Date: 06/27/2018 10:37:01 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Student]( [student_id] [nvarchar](50) NOT NULL, [gender] [nchar](10) NULL, [name] [nvarchar](50) NULL, [category] [nvarchar](50) NOT NULL, CONSTRAINT [PK_Student] PRIMARY KEY CLUSTERED ( [student_id] 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 INSERT [dbo].[Student]([student_id], [gender], [name], [category]) VALUES (N'1', N'1 ', N'1', N'1') INSERT [dbo].[Student]([student_id], [gender], [name], [category]) VALUES (N'2', N'2 ', N'2', N'2') /****** Object: Table [dbo].[Plan] Script Date: 06/27/2018 10:37:01 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Plan]( [plan_id] [nvarchar](50) NOT NULL, [audience_id] [nvarchar](50) NOT NULL, [course_id] [nvarchar](50) NOT NULL, CONSTRAINT [PK_Plan] PRIMARY KEY CLUSTERED ( [plan_id] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY], CONSTRAINT [IX_Plan] UNIQUE NONCLUSTERED ( [audience_id] ASC, [course_id] 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 INSERT [dbo].[Plan]([plan_id], [audience_id], [course_id]) VALUES (N'1', N'1', N'1') INSERT [dbo].[Plan]([plan_id], [audience_id], [course_id]) VALUES (N'2', N'2', N'2') /****** Object: Table [dbo].[Teach] Script Date: 06/27/2018 10:37:01 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Teach]( [teach_id] [nvarchar](50) NOT NULL, [plan_id] [nvarchar](50) NULL, [teacher_id] [nvarchar](50) NULL, CONSTRAINT [PK_Teach] PRIMARY KEY CLUSTERED ( [teach_id] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY], CONSTRAINT [IX_Teach_1] UNIQUE NONCLUSTERED ( [teach_id] ASC, [plan_id] 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 INSERT [dbo].[Teach]([teach_id], [plan_id], [teacher_id]) VALUES (N'1', N'1', N'1') INSERT [dbo].[Teach]([teach_id], [plan_id], [teacher_id]) VALUES (N'2', N'2', N'2') /****** Object: Table [dbo].[Student_Selete] Script Date: 06/27/2018 10:37:01 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Student_Selete]( [selete_id] [nvarchar](50) NOT NULL, [student_id] [nvarchar](50) NOT NULL, [teach_id] [nvarchar](50) NOT NULL, CONSTRAINT [PK_Student_Selete] PRIMARY KEY CLUSTERED ( [selete_id] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY], CONSTRAINT [IX_Student_Selete_1] UNIQUE NONCLUSTERED ( [student_id] ASC, [teach_id] 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 /****** Object: ForeignKey [audience_id] Script Date: 06/27/2018 10:37:01 ******/ ALTER TABLE [dbo].[Plan] WITH CHECK ADD CONSTRAINT [audience_id] FOREIGN KEY([audience_id]) REFERENCES [dbo].[audience]([audience_id]) GO ALTER TABLE [dbo].[Plan] CHECK CONSTRAINT [audience_id] GO /****** Object: ForeignKey [course_id] Script Date: 06/27/2018 10:37:01 ******/ ALTER TABLE [dbo].[Plan] WITH CHECK ADD CONSTRAINT [course_id] FOREIGN KEY([course_id]) REFERENCES [dbo].[Course]([course_id]) GO ALTER TABLE [dbo].[Plan] CHECK CONSTRAINT [course_id] GO /****** Object: ForeignKey [plan_id] Script Date: 06/27/2018 10:37:01 ******/ ALTER TABLE [dbo].[Teach] WITH CHECK ADD CONSTRAINT [plan_id] FOREIGN KEY([plan_id]) REFERENCES [dbo].[Plan]([plan_id]) GO ALTER TABLE [dbo].[Teach] CHECK CONSTRAINT [plan_id] GO /****** Object: ForeignKey [teacher_id] Script Date: 06/27/2018 10:37:01 ******/ ALTER TABLE [dbo].[Teach] WITH CHECK ADD CONSTRAINT [teacher_id] FOREIGN KEY([teacher_id]) REFERENCES [dbo].[Teacher]([teacher_id]) GO ALTER TABLE [dbo].[Teach] CHECK CONSTRAINT [teacher_id] GO /****** Object: ForeignKey [student_zhujian] Script Date: 06/27/2018 10:37:01 ******/ ALTER TABLE [dbo].[Student_Selete] WITH CHECK ADD CONSTRAINT [student_zhujian] FOREIGN KEY([student_id]) REFERENCES [dbo].[Student]([student_id]) GO ALTER TABLE [dbo].[Student_Selete] CHECK CONSTRAINT [student_zhujian] GO /****** Object: ForeignKey [teach_zhujian] Script Date: 06/27/2018 10:37:01 ******/ ALTER TABLE [dbo].[Student_Selete] WITH CHECK ADD CONSTRAINT [teach_zhujian] FOREIGN KEY([teach_id]) REFERENCES [dbo].[Teach]([teach_id]) GO ALTER TABLE [dbo].[Student_Selete] CHECK CONSTRAINT [teach_zhujian] GO 七 数据库关系图 最后贴一下朋友的数据库ER图和逻辑设计,是仓库管理系统,我觉得也可以参考: ER图: 逻辑图:

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Hadoop Pig学习笔记(一) 各种SQL在PIG中实现

我这里以Mysql 5.1.x为例,Pig的版本是0.8 同时我将数据放在了两个文件,存放在/tmp/data_file_1和/tmp/data_file_2中.文件内容如下: tmp_file_1: Txt代码 zhangsan 23 1 lisi 24 1 wangmazi 30 1 meinv 18 0 dama 55 0 zhangsan231 lisi241 wangmazi301 meinv180 dama550 tmp_file_2: Txt代码 1 a 23 bb 50 ccc 30 dddd 66 eeeee 1a 23bb 50ccc 30dddd 66eeeee 1.从文件导入数据 1)Mysql (Mysql需要先创建表). CREATE TABLE TMP_TABLE(USER VARCHAR(32),AGE INT,IS_MALE BOOLEAN); CREATE TABLE TMP_TABLE_2(AGE INT,OPTIONS VARCHAR(50)); -- 用于Join LOAD DATA LOCAL INFILE '/tmp/data_file_1' INTO TABLE TMP_TABLE ; LOAD DATA LOCAL INFILE '/tmp/data_file_2' INTO TABLE TMP_TABLE_2; 2)Pig tmp_table = LOAD '/tmp/data_file_1' USING PigStorage('\t') AS (user:chararray, age:int,is_male:int); tmp_table_2= LOAD '/tmp/data_file_2' USING PigStorage('\t') AS (age:int,options:chararray); 2.查询整张表 1)Mysql SELECT * FROM TMP_TABLE; 2)Pig DUMP tmp_table; 3. 查询前50行 1)Mysql SELECT * FROM TMP_TABLE LIMIT 50; 2)Pig tmp_table_limit = LIMIT tmp_table 50; DUMP tmp_table_limit; 4.查询某些列 1)Mysql SELECT USER FROM TMP_TABLE; 2)Pig tmp_table_user = FOREACH tmp_table GENERATE user; DUMP tmp_table_user; 5. 给列取别名 1)Mysql SELECT USER AS USER_NAME,AGE AS USER_AGE FROM TMP_TABLE; 2)Pig tmp_table_column_alias = FOREACH tmp_table GENERATE user AS user_name,age AS user_age; DUMP tmp_table_column_alias; 6.排序 1)Mysql SELECT * FROM TMP_TABLE ORDER BY AGE; 2)Pig tmp_table_order = ORDER tmp_table BY age ASC; DUMP tmp_table_order; 7.条件查询 1)Mysql SELECT * FROM TMP_TABLE WHERE AGE>20; 2) Pig tmp_table_where = FILTER tmp_table by age > 20; DUMP tmp_table_where; 8.内连接Inner Join 1)Mysql SELECT * FROM TMP_TABLE A JOIN TMP_TABLE_2 B ON A.AGE=B.AGE; 2)Pig tmp_table_inner_join = JOIN tmp_table BY age,tmp_table_2 BY age; DUMP tmp_table_inner_join; 9.左连接Left Join 1)Mysql SELECT * FROM TMP_TABLE A LEFT JOIN TMP_TABLE_2 B ON A.AGE=B.AGE; 2)Pig tmp_table_left_join = JOIN tmp_table BY age LEFT OUTER,tmp_table_2 BY age; DUMP tmp_table_left_join; 10.右连接Right Join 1)Mysql SELECT * FROM TMP_TABLE A RIGHT JOIN TMP_TABLE_2 B ON A.AGE=B.AGE; 2)Pig tmp_table_right_join = JOIN tmp_table BY age RIGHT OUTER,tmp_table_2 BY age; DUMP tmp_table_right_join; 11.全连接Full Join 1)Mysql SELECT * FROM TMP_TABLE A JOIN TMP_TABLE_2 B ON A.AGE=B.AGE UNION SELECT * FROM TMP_TABLE A LEFT JOIN TMP_TABLE_2 B ON A.AGE=B.AGE UNION SELECT * FROM TMP_TABLE A RIGHT JOIN TMP_TABLE_2 B ON A.AGE=B.AGE; 2)Pig tmp_table_full_join = JOIN tmp_table BY age FULL OUTER,tmp_table_2 BY age; DUMP tmp_table_full_join; 12.同时对多张表交叉查询 1)Mysql SELECT * FROM TMP_TABLE,TMP_TABLE_2; 2)Pig tmp_table_cross = CROSS tmp_table,tmp_table_2; DUMP tmp_table_cross; 13.分组GROUP BY 1)Mysql SELECT * FROM TMP_TABLE GROUP BY IS_MALE; 2)Pig tmp_table_group = GROUP tmp_table BY is_male; DUMP tmp_table_group; 14.分组并统计 1)Mysql SELECT IS_MALE,COUNT(*) FROM TMP_TABLE GROUP BY IS_MALE; 2)Pig tmp_table_group_count = GROUP tmp_table BY is_male; tmp_table_group_count = FOREACH tmp_table_group_count GENERATE group,COUNT($1); DUMP tmp_table_group_count; 15.查询去重DISTINCT 1)MYSQL SELECT DISTINCT IS_MALE FROM TMP_TABLE; 2)Pig tmp_table_distinct = FOREACH tmp_table GENERATE is_male; tmp_table_distinct = DISTINCT tmp_table_distinct; DUMP tmp_table_distinct; 本文作者:佚名 来源:51CTO

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