SQL Graph: список всех путей от корня до объектов различных типов

Question

Учитывая иерархию частей продукта:

Car -> BodyWork
 |
 V
Wheel -> Tyre

И некоторые детали, имеющие информацию о поставщике

Car -> Tesla
Tyre -> Continental

Как вы перечисляете все пути, ведущие к деталям и, возможно, поставщикам?Также должны быть определенные столбцы для достигнутой детали или поставщика, возможно, содержащие значения NULL.

Представьте себе дорогу, ведущую к различным вещам (детали, поставщики), и запрос будет возвращать все достигнутые вещи, перечисляяпути и возвращая объекты разных типов в разные столбцы, для которых в противном случае установлено значение NULL.

Answer 1

CREATE TABLE PRODUCT (
    ProductID int not null identity primary key,
    ProductName varchar(50) 
) AS Node;

INSERT INTO PRODUCT(ProductName) VALUES ('Car'),('BodyWork'),('Wheel'),('Tyre');

CREATE TABLE SUPPLIER (
    SuppierID int not null identity primary key,
    SupplierName varchar(50)    
) AS Node;

INSERT INTO SUPPLIER(SupplierName) VALUES ('Continental'),('Tesla');

CREATE TABLE HAS_PART AS EDGE;

INSERT INTO HAS_PART ($from_id, $to_id)
VALUES ((SELECT $node_id FROM PRODUCT WHERE ProductName='Car'), (SELECT $node_id FROM PRODUCT WHERE ProductName='BodyWork'))
,((SELECT $node_id FROM PRODUCT WHERE ProductName='Car'), (SELECT $node_id FROM PRODUCT WHERE ProductName='Wheel'))
,((SELECT $node_id FROM PRODUCT WHERE ProductName='Wheel'), (SELECT $node_id FROM PRODUCT WHERE ProductName='Tyre'));

CREATE TABLE SUPPLIED_BY AS EDGE;

INSERT INTO SUPPLIED_BY ($from_id, $to_id)
VALUES ((SELECT $node_id FROM PRODUCT WHERE ProductName='Car'), (SELECT $node_id FROM SUPPLIER WHERE SupplierName='Tesla'))
,((SELECT $node_id FROM PRODUCT WHERE ProductName='Tyre'), (SELECT $node_id FROM SUPPLIER WHERE SupplierName='Continental'));

SELECT * FROM HAS_PART;
SELECT * FROM SUPPLIED_BY;

CREATE VIEW All_nodes AS
SELECT ProductID, ProductName, NULL AS SupplierID, NULL AS SupplierName, ProductName AS NodeName FROM PRODUCT
UNION ALL
SELECT NULL, NULL, SuppierID, SupplierName , SupplierName AS NodeName FROM SUPPLIER;

CREATE VIEW All_edges AS
SELECT * FROM HAS_PART
UNION ALL
SELECT * FROM SUPPLIED_BY;

SELECT
       P1.ProductID,
       P1.ProductName,
       COUNT(P2.NodeName) WITHIN GROUP (GRAPH PATH) AS [Depth],
       STRING_AGG(P2.NodeName,'->') WITHIN GROUP (GRAPH PATH) AS [Assembly],
       LAST_VALUE(P2.ProductID) WITHIN GROUP (GRAPH PATH) AS [Final Product ID],
       LAST_VALUE(P2.SupplierID) WITHIN GROUP (GRAPH PATH) AS [Final Supplier ID],
       LAST_VALUE(P2.ProductName) WITHIN GROUP (GRAPH PATH) AS [Final Product Name],
       LAST_VALUE(P2.SupplierName) WITHIN GROUP (GRAPH PATH) AS [Final Supplier Name]
FROM
       All_nodes P1,
       All_nodes FOR PATH P2,
       All_edges FOR PATH HP
WHERE MATCH(SHORTEST_PATH(P1(-(HP)->P2)+))
AND P1.ProductID = 1
ORDER BY P1.ProductID;