[英]combine two SQL queries
SELECT Student.S_ID, COUNT(*) AS **Final_Exam_Level**
FROM Student, Exams, Exam_Allocation
WHERE (Student.S_ID)=Exam_Allocation.S_ID
And ((Exams.Exam_ID)=Exam_Allocation.Exam_ID)
And (Exams.Date_Taken) <= #12/31/2010#
GROUP BY Student.S_ID, Student.Course_Level
ORDER BY Student.S_ID;
SELECT Student.S_ID AS S_ID, Student.First_Name AS First_Name, Student.Surname AS Surname, MAX(New_Models.Date_Issued) AS Last_Course_Date, MAX(New_Models.Issue) AS Last_Issue, MAX(New_Models.Model_ID) AS Last_Model_ID, Student.Course_Level AS No_Training_Courses
FROM New_Models, New_Models_Allocation, Student
WHERE New_Models.Model_ID=New_models_Allocation.Model_ID And Student.S_ID=New_Models_Allocation.S_ID
GROUP BY Student.S_ID, Student.Course_Level, First_Name, Surname
ORDER BY MAX(New_Models.Model_ID) DESC;
如何將 Final_Exam_Level 添加到第二個查詢中?
Final_Exam_Level 計算每個學生做了多少 Exam_ID。 Exam_Allocation 有兩個外鍵,S_Id 和 Exam_ID
select Query_New_Models.*, Query_Exam.Final_Exam_Level
FROM (SELECT Student.S_ID AS S_ID, Student.First_Name AS First_Name, Student.Surname AS Surname, MAX(New_Models.Date_Issued) AS Last_Course_Date, MAX(New_Models.Issue) AS Last_Issue, MAX(New_Models.Model_ID) AS Last_Model_ID, Student.Course_Level AS No_Training_Courses
FROM New_Models, New_Models_Allocation, Student
WHERE New_Models.Model_ID=New_models_Allocation.Model_ID And Student.S_ID=New_Models_Allocation.S_ID
GROUP BY Student.S_ID, Student.Course_Level
ORDER BY MAX(New_Models.Model_ID) DESC) INNER JOIN (SELECT Student.S_ID, COUNT(*) AS Final_Exam_Level
FROM Student, Exams, Exam_Allocation
WHERE (Student.S_ID)=Exam_Allocation.S_ID
And ((Exams.Exam_ID)=Exam_Allocation.Exam_ID)
And (Exams.Date_Taken)<=#12/31/2010#
GROUP BY Student.S_ID, Student.Course_Level
ORDER BY Student.S_ID
) ON Query_Exam.S_ID = Query_New_Models.S_ID ;
只需將它們都變成更高查詢的子查詢
select Second.*, First.Final_Exam_Level
from (Your Second Query Here) Second
inner join
(Your First Query Here) First on First.Technician_ID = Second.Technician_ID
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