Left join together with inner join in ms-access
Solution 1
I re-created your query in Access' query designer. The query worked with both joins as INNER, as you found. However, the query designer complained about "ambiguous outer join" when I tried to switch the first INNER JOIN to LEFT JOIN. LEFT for both joins works, as does INNER for both.
If you need LEFT for the first join and INNER for the second, you can move the tables from the second join into a subquery.
SELECT
School.[Name] AS school_name,
sub.[Name] AS student_name,
sub.Grade
FROM
School LEFT JOIN (
SELECT
Student.SchoolID,
Student.[Name],
Grade.Grade
FROM
Student INNER JOIN Grade
ON Student.GradeID = Grade.ID) AS sub
ON School.ID = sub.SchoolID;
Solution 2
Student
.GradeID
might be null, because you did a LEFT JOIN on Student, it might not exist for your second join.
So basically, whenever you do a LEFT JOIN, you cannot use any of those TABLES columns in future JOINS
Dulini Atapattu
Graduated as a Bachelor of Science in Computer Science at University of Colombo School of Computing, Sri Lanka. Final year research: Node Similarity Abstraction for Wireless Sensor Networks. Enthusiast in Computer Science related research, new technologies and R&D work. Hobbies include photography and cookery...
Updated on June 04, 2022Comments
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Dulini Atapattu about 2 years
I have to run the following query in an access database:
SELECT School.Name, Student.Name, Grade.Grade FROM( (`School` `School` LEFT JOIN `Student` `Student` ON `School`.`ID`=`Student`.`SchoolID`) INNER JOIN `Grade` `Grade` ON `Student`.`GradeID` = `Grade`.`ID`)
This gives me the error "Join expression not supported", but if I change the LEFT JOIN to INNER JOIN, it runs correctly. I think the way of using both these joins together on ms-access can have a different way. Can anyone pls tell me what is wrong in this query and/ or the reason that this is not supported.
Thanks
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Richard Schneider about 13 yearsI don't know you column names for each table, but it would something like: left join Student.ID = Grade.StudentID left join School.ID = Student.SchoolID
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Jeeva J about 5 yearsCan we avoid subquery in the left join?
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HansUp about 5 yearsPerhaps
School LEFT JOIN (Student INNER JOIN)
would do it. Beware Access is demanding about parentheses in theFROM
clause. if you're not familiar with the details, suggest you use the query designer to set up your joins.