Question

I am trying to create a query that lists records from table 1 along with a status based on corresponding records in table 2 that have null values in one or more of the fields. The problem I am running into is how to include records from table 1 which have no corresponding record in table 2.

In my example, I want to list the names of all students in tblStudent along with a field indicating the status of their schedule in tblStudentSchedule. If either course or teacher field in tblStudentSchedule is Null or no corresponding record in tblStudentSchedule is found then I want to display “Incomplete”. Otherwise, I want to display “Complete”.

desired result

Name  | Schedule Status
-----------------------
Bob   | Incomplete     
Sally | Incomplete
Jane  | Incomplete
Matt  | Incomplete
Jim   | Complete

I’m working in Access. I would post my query attempts but I think they would just confuse the issue. This is probably very basic but I am having a mental block trying to wrap my brain around this one.

tblStudent

studentID | studentName
-----------------------
1         | Bob
2         | Sally
3         | Jane
4         | Matt
5         | Jim

tblStudentSchedule

studentID | period | course | teacher
-------------------------------------
1         | 1      | math   | Jones
1         | 2      | <null> | Watson
2         | 1      | reading| <null>
4         | 1      | <null> | Crick
5         | 1      | math   | Jones

Answer 1

select  s.studentName as Name
,       iif(sum(iif(ss.course is null or ss.teacher is null, 1, 0)) = 0,
            'Complete', 'Incomplete')
        as [Schedule Status]
from    tblStudent s
left join    
        tblStudentSchedule ss
on      ss.studentID = s.studentID
group by
        s.studentName 

A left join returns a single row with null when a match is not found. So the check on ss.course is null will also trigger when the student is absent from the schedule table.