Query to get all siblings - sql

Question

I have table like that:
ID NAME SURNAME MotherID FatherID
0 JJ smi NULL NULL
1 ja rly NULL NUL
2 ak smi 0 1
3 ol smi 0 1
4 oa woo 2 3
5 oe boo 2 3
etc.
I need query that with specific parameter as NAME and surname will return me all siblings of a person.
Expected output
NAME SURNAME FATHERNAME FATHERSURNAME MOTHERNAME MOTHERSURNAME
AK SMI JA RLY JJ SMI
OL SMI JA RLY JJ SMI
I tried
SELECT
a.name,
a.surname
FROM PEOPLE a, PEOPLE b
WHERE (b.name = 'ak' AND b.surname ='smi' AND
(b.motherID = a.ID OR b.fatherid = ID))

Answer 1

You can use a SUB QUERY to achieve this.
Table Creation:
DECLARE #T TABLE(
ID INT,
NAME VARCHAR(MAX),
SURNAME VARCHAR(MAX),
MOTHERID INT,
FATHERID INT)
Table Insertion:
Insert into #t Values(0,'JJ','smi',NULL,NULL)
Insert into #t Values(1,'ja','rly',NULL,NULl)
Insert into #t Values(2,'ak','smi',0,1)
Insert into #t Values(3,'ol','smi',0,1)
Insert into #t Values(4,'oa','woo',2,3)
Insert into #t Values(5,'oe','boo',2,3)
Query:
SELECT S.NAME AS NAME,S.SURNAME AS SURNAME,S.FATHER_NAME ,S.FATHER_SURNAME,M.NAME AS
MOTHER_NAME,M.SURNAME AS MOTHER_SURNAME
FROM #T M INNER JOIN(
SELECT T2.NAME AS NAME,T2.SURNAME AS SURNAME,T1.NAME AS FATHER_NAME,T1.SURNAME AS
FATHER_SURNAME,T2.MOTHERID
FROM #T T1
INNER JOIN #T T2 ON T1.ID=T2.FATHERID
WHERE T2.NAME IN ('AK','OL'))S ON M.ID=S.MOTHERID
Output:
Also ,add the WHERE clause based on your parameter requirement.

Answer 2

Here is one way you can get it. From here you can explore a few other options!
CREATE PROC GetSiblings
(
#GivenName AS VARCHAR(100),
#SurName AS VARCHAR(100)
)
AS
BEGIN
SET NOCOUNT ON;
SELECT
A.GivenName,
A.SurName,
F.GivenName AS FatherGivenName,
F.SurName AS FatherSurName,
M.GivenName AS MotherGivenName,
M.SurName AS MotherSurName,
FROM PEOPLE AS P INNER JOIN PEOPLE AS F ON P.FatherID = F.ID
INNER JOIN PEOPLE AS M ON P.MotherID = M.ID
WHERE P.GivenName = #GivenName AND P.SurName = #SurName
UNION --By father
SELECT
A.GivenName,
A.SurName,
F.GivenName AS FatherGivenName,
F.SurName AS FatherSurName,
M.GivenName AS MotherGivenName,
M.SurName AS MotherSurName,
FROM PEOPLE AS P INNER JOIN PEOPLE AS F ON P.FatherID = F.ID
INNER JOIN PEOPLE AS M ON P.MotherID = M.ID
WHERE P.FatherID IN (SELECT DISTINCT FatherID FROM PEOPLE WHERE GivenName = #GivenName AND SurName = #SurName)
UNION --By mother
SELECT
A.GivenName,
A.SurName,
F.GivenName AS FatherGivenName,
F.SurName AS FatherSurName,
M.GivenName AS MotherGivenName,
M.SurName AS MotherSurName,
FROM PEOPLE AS P INNER JOIN PEOPLE AS F ON P.FatherID = F.ID
INNER JOIN PEOPLE AS M ON P.MotherID = M.ID
WHERE P.MotherID IN (SELECT DISTINCT MotherID FROM PEOPLE WHERE GivenName = #GivenName AND SurName = #SurName);
END;