Reordering the results of an SQL query using SQLite - sql

Question

I have a SQLite database that models Sanskrit nouns and has tables like this: (Sorry if it is very lengthy. I've tried to cut things down to the minimum necessary to understand this problem.)
numbers:
id
number
1
singular
2
dual
3
plural
cases:
id
case
1
nominative
2
accusative
3
instrumental
4
dative
5
ablative
6
genitive
7
locative
8
vocative
nouns:
id
name
1
rAma
forms:
id
form
noun
1
rAmaH
1
2
rAmau
1
3
rAmAH
1
4
rAmam
1
5
rAmAN
1
6
rAmENa
1
7
rAmAbhyAm
1
8
rAmaiH
1
9
rAmAya
1
10
rAmebhyaH
1
11
rAmAt
1
12
rAmasya
1
13
ramayoH
1
14
rAmANAm
1
15
rAme
1
16
rAmeShu
1
17
rAma
1
noun is a foreign key which references nouns(id)
nounforms:
id
form
case
number
noun
1
1
1
1
1
2
2
1
2
1
3
3
1
3
1
4
4
2
1
1
5
2
2
2
1
6
5
2
3
1
7
6
3
1
1
8
7
3
2
1
9
8
3
3
1
10
9
4
1
1
11
7
4
2
1
12
10
4
3
1
13
11
5
1
1
14
7
5
2
1
15
10
5
3
1
16
12
6
1
1
17
13
6
2
1
18
14
6
3
1
19
15
7
1
1
20
13
7
2
1
21
16
7
3
1
22
17
8
1
1
23
2
8
2
1
24
3
8
3
1
form is a foreign key which references forms(id)
case is a foreign key which references cases(id)
number is a foreign key which references numbers(id)
noun is a foreign key which references nouns(id)
I can get all the declensions of the noun rAma with this SQL query:
SELECT forms.form FROM forms JOIN nouns,nounforms
WHERE forms.id = nounforms.form
AND nounforms.noun = nouns.id
AND noun.name = "rAma"
GROUP BY nounforms.case, nounforms.number;
and that returns the whole noun perfectly in 24 rows:
form
rAmaH
rAmau
rAmAH
rAmam
rAmau
rAmAN
rAmENa
rAmAbhyAm
rAmaiH
rAmAya
rAmAbhyAm
rAmebhyaH
rAmAt
rAmAbhyAm
rAmebhyaH
rAmasya
ramayoH
rAmANAm
rAme
ramayoH
rAmeShu
rAma
rAmau
rAmAH
So far so good. But what I would really like is something like this:
singular
dual
plural
rAmaH
rAmau
rAmAH
rAmam
rAmau
rAmAN
rAmENa
rAmAbhyAm
rAmaiH
rAmAya
rAmAbhyAm
rAmebhyaH
rAmAt
rAmAbhyAm
rAmebhyaH
rAmasya
ramayoH
rAmANAm
rAme
ramayoH
rAmeShu
rAma
rAmau
rAmAH
i.e. 8 rows for each case with 3 columns for each number. The problem is my SQL knowledge is not quite enough to get me there. I think what I want is a view or a virtual table. Is that right? Also once that is solved, I would like to parametrize the query so I can use it for nouns other than rAma but SQLite does not I believe support stored procedures. Is that right? If so, what is the workaround?
Btw, I am aware that I can do the reordering in my application. In fact, that is what I am
doing now but I would like to keep as much centralized in the database as possible so I can port to other languages/environments.
Can anyone help?

Answer 1

You need conditional aggregation:
SELECT MAX(CASE WHEN nf.number = 1 THEN f.form END) singular,
MAX(CASE WHEN nf.number = 2 THEN f.form END) dual,
MAX(CASE WHEN nf.number = 3 THEN f.form END) plural
FROM forms f
JOIN nouns n ON n.id = f.noun
JOIN nounforms nf ON f.id = nf.form AND nf.noun = n.id
WHERE n.name = ?
GROUP BY nf.`case`;
Replace the placeholder ? with the noun that you want.
Also, always use proper joins with ON clauses and aliases for the tables to make the code shorter and more readable.
See the demo.
As you already know, SQLite does not support stored procedures or functions, so probably the best way to use this query is as it is in your app with the the placeholder ? in a prepared statement and pass the value of the noun as a parameter.