從不同的表中檢索數據（SQL Server）的

Question

我有一個SQL Server數據庫中4代表與下面的模式：

1. 出席

   CREATE TABLE [dbo].[Attendance] (
   [AttendanceId] UNIQUEIDENTIFIER DEFAULT (newid()) NOT NULL, 
   [CourseId]  UNIQUEIDENTIFIER NOT NULL, 
   [StudentId] UNIQUEIDENTIFIER NOT NULL, 
   [SubjectId] UNIQUEIDENTIFIER NOT NULL, 
   [Semester]  INT    NOT NULL, 
   [Month]  NVARCHAR (50) NOT NULL, 
   [Count]  INT    NOT NULL, 
   CONSTRAINT [PK_Attendance] PRIMARY KEY NONCLUSTERED ([AttendanceId] ASC), 
   CONSTRAINT [FK_Attendance_Student] FOREIGN KEY ([StudentId]) REFERENCES [dbo].[Student] ([StudentId])); 
   

2. 場

   CREATE TABLE [dbo].[Course] (
   [CourseId] UNIQUEIDENTIFIER DEFAULT (newid()) NOT NULL, 
   [Name]  NVARCHAR (50) NOT NULL, 
   CONSTRAINT [PK_Course] PRIMARY KEY NONCLUSTERED ([CourseId] ASC) 
   ); 
   

3. 學生

   CREATE TABLE [dbo].[Student] (
   [StudentId] UNIQUEIDENTIFIER DEFAULT (newid()) NOT NULL, 
   [CourseId] UNIQUEIDENTIFIER NOT NULL, 
   [Name]  NVARCHAR (100) NOT NULL, 
   [RollNo] INT    NOT NULL, 
   [Semester] INT    NOT NULL, 
   CONSTRAINT [PK_Student] PRIMARY KEY NONCLUSTERED ([StudentId] ASC), 
   CONSTRAINT [FK_Student_Course] FOREIGN KEY ([CourseId]) REFERENCES [dbo].[Course] ([CourseId]) 
   ); 
   

4. 主題

   CREATE TABLE [dbo].[Subject] (
   [SubjectId] UNIQUEIDENTIFIER DEFAULT (newid()) NOT NULL, 
   [CourseId] UNIQUEIDENTIFIER NOT NULL, 
   [Name]  NVARCHAR (100) NOT NULL, 
   [Semester] INT    NOT NULL, 
   CONSTRAINT [PK_Subject] PRIMARY KEY NONCLUSTERED ([SubjectId] ASC), 
   CONSTRAINT [FK_Subject_Course] FOREIGN KEY ([CourseId]) REFERENCES [dbo].[Course] ([CourseId]) 
   ); 
   

我需要在以下格式創建出席報告：

課程名稱 | 學生姓名 | 使用者名稱 | 學期 | 月 | 計數

請告訴我需要使用什麼SQL查詢，如果需要更改模式，則建議使用相同的SQL查詢。

我期待着您的回覆。

感謝，

Answer 1

你需要在查詢中使用一個JOIN所以它只返回從考勤表匹配[StudentId]的行。

例如

SELECT c.CourseName, s.StudentName, u.SubjectName, u.Semester, a.Month, a.Count 
FROM Student s 
    JOIN Attendance a ON s.StudentId = a.StudentId 
    JOIN Course c ON a.CourseId = c.CourseId 
    JOIN Subject u ON c.CourseId = u.CourseId 

東西沿着這些線路將只返回的具體匹配