Display titles which are missing association values partially or completely - sql

Question

I am having problem writing SQL query for the following scenario. I need someone's help to write the query.
I have the following tables 7 tables:
1) Titles
ID Title Author
-------------------------------------------------------------------------
1 The Hidden Language of Computer Hardware and Software Charles Petzold
2 Paths, Dangers, Strategies Nick Bostrom
3 The Smart Girl's Guide to Privacy Violet Blue
4 Introduction to Algorithms Thomas H. Cormen
5 Machine Learning in Action Peter Harrington
...
2) Themes
ID Name
------------------------------------------
1 Science Fiction
2 Biography
3 Painting
...
3) Subjects
ID Name
-----------------------------------
1 Science
2 Technology
3 Music
4 Geography
...
4) Grades
ID Name
------------------------------------
1 Grade 1
2 Grade 2
3 Grade 3
4 Grade 4
5 Grade 5
...
5) TitleThemeAssociation
TitleID ThemeID
------------------------------------------
1 1
1 3
4 2
4 3
...
6) TitleSubjectAssociaton
TitleID SubjectID
---------------------------------
1 1
1 3
2 1
2 3
4 1
4 2
...
7) TitleGradeAssociaton
TitleID GradeID
1 1
1 2
1 3
2 1
2 2
...
I need to write a query to display only titles which are missing any of three values (Themes, Subjects and Grades) or not assigned values completely. I should not display the title if all three values (Themes, Subjects, Grades) are assigned. In the above data set since TitleID 1 has all three values it should not be present in the list. TitleID 2 has only Subjects and Grades assigned but not Themes so it should be displayed in the output. While listing the titles if a title has multiple values then they should be contacted with comma (,) separator.
So the final output of the above data set should be as below:
Output:
Title ID Title Theme Subject Grade
-------------------------------------------------------------------------------------------
2 Paths, Dangers, Strategies - Science, Music Grade 1, Grade 2
3 The Smart Girl's Guide to Privacy - - -
4 Introduction to Algorithms Biography, Painting Science, Technology -
5 Machine Learning in Action - - -

Answer 1

There are essentially two questions you're asking. The first being how to filter when either a Theme, Subject or Grade is missing. And the other is asking how to concat these items into a comma separated list.
The following query should be what you're looking for:
Select Distinct
T.Id As [Title ID],
T.Title,
H.Theme,
S.Subject,
G.Grade
From Titles T
Outer Apply
(
Select Stuff(( Select ', ' + Name
From Themes H
Join TitleThemeAssociation TH On H.Id = TH.ThemeId
Where TH.TitleId = T.Id
For Xml Path('')), 1, 2, '') As Theme
From Themes
) H
Outer Apply
(
Select Stuff(( Select ', ' + Name
From Subjects S
Join TitleSubjectAssociaton TS On S.Id = TS.SubjectId
Where TS.TitleId = T.Id
For Xml Path('')), 1, 2, '') As Subject
From Subjects
) S
Outer Apply
(
Select Stuff(( Select ', ' + Name
From Grades G
Join TitleGradeAssociaton TG On G.Id = TG.GradeId
Where TG.TitleId = T.Id
For Xml Path('')), 1, 2, '') As Grade
From Grades
) G
Where H.Theme Is Null
Or S.Subject Is Null
Or G.Grade Is Null

Answer 2

Hope this Helps.
;WITH cte_Titles (ID,Title,Author) AS
(
SELECT 1,'The Hidden Language of Computer Hardware and Software','Charles Petzold' UNION ALL
SELECT 2,'Paths, Dangers, Strategies','Nick Bostrom' UNION ALL
SELECT 3,'The Smart Girls Guide to Privacy','Violet Blue' UNION ALL
SELECT 4,'Introduction to Algorithms','Thomas H. Cormen' UNION ALL
SELECT 5,'Machine Learning in Action','Peter Harrington'
),cte_Themes(ID,Name) AS
(
SELECT 1,'Science Fiction' UNION ALL
SELECT 2,'Biography' UNION ALL
SELECT 3,'Painting'
),cte_Subjects(ID,Name) AS
(
SELECT 1,'Science' UNION ALL
SELECT 2,'Technology' UNION ALL
SELECT 3,'Music' UNION ALL
SELECT 4,'Geography'
),cte_Grades(ID,Name) AS
(
SELECT 1,'Grade 1' UNION ALL
SELECT 2,'Grade 2' UNION ALL
SELECT 3,'Grade 3' UNION ALL
SELECT 4,'Grade 4' UNION ALL
SELECT 5,'Grade 5'
),cte_TitleThemeAssociation(TitleID,ThemeID) AS
(
SELECT 1,1 UNION ALL
SELECT 1,3 UNION ALL
SELECT 4,2 UNION ALL
SELECT 4,3
),cte_TitleSubjectAssociaton(TitleID,SubjectID) AS
(
SELECT 1, 1 UNION ALL
SELECT 1, 3 UNION ALL
SELECT 2, 1 UNION ALL
SELECT 2, 3 UNION ALL
SELECT 4, 1 UNION ALL
SELECT 4, 2
),cte_TitleGradeAssociaton(TitleID,GradeID) AS
(
SELECT 1, 1 UNION ALL
SELECT 1, 2 UNION ALL
SELECT 1, 3 UNION ALL
SELECT 2, 1 UNION ALL
SELECT 2, 2
)
,cte_ResultSet AS
(
SELECT DISTINCT t.ID AS TitleID,
t.Title,
th.NAME AS Theme,
s.NAME AS Subject,
g.NAME AS Grade
FROM cte_Titles t
LEFT JOIN cte_TitleThemeAssociation tta
ON t.ID = tta.TitleID
LEFT JOIN cte_Themes th
ON tta.ThemeID = th.ID
LEFT JOIN cte_TitleSubjectAssociaton tsa
ON tsa.TitleID = t.ID
LEFT JOIN cte_Subjects s
ON tsa.SubjectID = s.ID
LEFT JOIN cte_TitleGradeAssociaton tga
ON tga.TitleID = t.ID
LEFT JOIN cte_Grades g
ON g.ID = tga.GradeID
)
SELECT DISTINCT Title
, STUFF((SELECT DISTINCT ',' + SUB.Theme AS [text()]
FROM cte_ResultSet SUB
WHERE SUB.TitleID = CAT.TitleID
FOR XML PATH('')
), 1, 1, '' ) AS Theme
, STUFF((SELECT DISTINCT ',' + SUB.Subject AS [text()]
FROM cte_ResultSet SUB
WHERE SUB.TitleID = CAT.TitleID
FOR XML PATH('')
), 1, 1, '' ) AS Subject
, STUFF((SELECT DISTINCT ',' + SUB.Grade AS [text()]
FROM cte_ResultSet SUB
WHERE SUB.TitleID = CAT.TitleID
FOR XML PATH('')
), 1, 1, '' ) AS Grade
FROM cte_ResultSet CAT