Question

Can anybody please show me how to make a view as multiple left join?

A GAME has zero or multiple LINKs (OneToMany on GAME.ID = LINK.GAME_ID)
Each LINK has exactly one of multiple STOREs (OneToOne on LINK.STORE_ID = STORE.ID)
Each STORE has exactly one of multiple PLATFORMs (OneToOne on STORE.PLATFORM_ID = PLATFORM.ID)

And I want to make a VIEW as

PLATFORM_ID (FK)    GAME_ID (FK)
--------------------------------

I mean I want to list GAMEs, by the given PLATFORM, which each has at least one or more paths through LINK and STORE to the PLATFORM

Thank you.

Answer 1

SELECT DISTINCT s.PLATFORM_ID, l.GAME_ID
FROM Games g 
LEFT JOIN Links l ON g.ID = l.GAME_ID
INNER JOIN Stores ON l.STORE_ID = s.STORE_ID
INNER JOIN PLATFORMS p ON s.PLATFORM_ID = p.ID